Why Descartes’s “By Their Very Nature” Claim Does Not Apply To Every Cartesian Idea — Ring

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Abstract

Descartes’s claim that the objective mode of being belongs to ideas “by their very nature” (AT VII 42; CSM II 29) appears to support a universal-objective-reality thesis: every Cartesian idea, simply because it is an idea, contains objectively real representational content (OR). That reading is too broad. The passage occurs inside the Third Meditation causal proof, where Descartes is considering ideas under their objective aspect, that is, insofar as they represent or exhibit things with differing degrees of objective reality. It should therefore be read as a thesis about strict ideas, not about every item Descartes elsewhere calls an idea in the broad sense. Strict ideas possess objective reality by their nature because to be a strict idea is to be one of the tanquam rerum imagines [as if images of things], and for Descartes the being that such represented content has in the mind just is objective being.

Broad ideas, by contrast, include immediately perceived occurrent thoughts such as willing, fearing, affirming, denying, and sensing. A single such thought may be considered with respect to its representational character and also with respect to its volitional, affective, judicative, or sensory character, without implying that these must be separate components of the thought. But considering a cognition with respect to its representational character is not a guarantee that every content within it is OR-bearing. A cognition may present positive phenomenal or intelligible content without thereby supplying an OR-bearing representatum [item represented] of the kind ranked by the causal proof. The correct conclusion is not that Descartes’s “by their very nature” claim is false, but that its scope is restricted: objective reality belongs by nature to ideas insofar as they are strict representational ideas, not to every conscious mode that can be called an idea in the broader Cartesian usage. Three independently argued cases support the conclusion that the universal thesis is false: some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation. In the sensory case, positive phenomenal content occurs formally without constituting an OR-bearing internal representation.

Introduction

Why has Descartes’s “by their very nature” claim been taken to apply to every Cartesian idea? In the Third Meditation, Descartes writes: “iste modus essendi objectivus competit ideis ex ipsarum naturâ.” [This objective mode of being belongs to ideas from their own nature.] (AT VII 42; CSM II 29)¹The CSM translation reads: “For just as the objective mode of being belongs to ideas by their very nature, so the formal mode of being belongs to the causes of ideas—or at least the first and most important ones—by their very nature.” (AT VII 42; CSM II 29)

Taken in isolation, Descartes appears to be claiming that every item he calls an idea must contain objective reality, since the objective mode of being belongs to ideas by their very nature. This is the universal-objective-reality reading.²See my posts arguing the falsity of the universal readings: “Do Cartesian Sensations Have Objective Reality?: Strict Ideas, Broad Ideas, And Material Falsity In Descartes’s Theory Of Ideas,” “Condensation: Why Objective Reality Cannot Be Descartes’s Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict Idea Model,” its companion piece “Why Objective Reality Cannot Be Universal In Descartes’s Theory Of Ideas: Nothing, Eternal Truths, Sensations, And Fear With Claude Opus 4.6,” and “The Core DTOI Argument: Sensations Without Cartesian Objective Reality.”
On this reading, every sensation, volition, passion, judgment, fear, desire, affirmation, and every other immediately perceived mental mode must contain objectively real representational content. The next three passages show why the scope of Descartes’s claim requires careful attention. Although each connects ideas with objective reality or representation, they differ in how explicitly they extend that connection to all ideas.

Kurt Smith writes that ideas possess objective reality by their very nature, and that only ideas possess both formal and objective reality:

“Descartes says that ideas possess objective reality by their very nature. Equally importantly, ideas are the only items in his ontology that possess both formal and objective reality.” (Kurt Smith, “Descartes’ Theory of Ideas,” §2; citing AT VII 42; CSM II 29)

“Descartes very clearly says that ideas are the items in his ontology that possess objective reality, and they possess it by their very nature.” (Kurt Smith, “Descartes’ Theory of Ideas,” §5; citing AT VII 42; CSM II 29)³Kurt Smith, “Descartes’ Theory of Ideas,” Stanford Encyclopedia of Philosophy, §2, “Ideas and the Formal–Objective Reality Distinction,” third paragraph, and §5, “The Rules: Simple Natures and the Concepts of Clarity and Distinctness,” final paragraph.

What happens if “ideas” receives no restriction? The statement then treats AT VII 42; CSM II 29 as a doctrine about the essence of ideas as such: wherever there is an idea, there is objective being, because that mode of being belongs to an idea by nature. Whether Smith’s formulation carries that unrestricted scope depends on the operative sense of “idea.”

Steven Nadler  treats objective reality as a defining feature of ideas, and he reaches that result by placing the strict-name restriction of AT VII 37; CSM II 25 immediately beside the “by their very nature” sentence of AT VII 42; CSM II 29.

“We can say, in fact, that for Descartes objective reality is a defining feature of the mind’s ideas: ‘Some of my thoughts are as it were images of things, and it is only in these cases that the term “idea” is strictly appropriate.’ It is essential to an idea that it has a representational content that it displays to the mind. ‘The objective mode of being belongs to ideas by their very nature.’” (Steven Nadler, “The Doctrine of Ideas,” 93; Descartes passages at AT VII 37, 42; CSM II 25, 29)⁴Steven Nadler, “The Doctrine of Ideas,” in The Blackwell Guide to Descartes’ Meditations, ed. Stephen Gaukroger (Malden, MA: Blackwell, 2006), 93. For a comparative placement of this reading among other commentators, see my “A Hyperlinked Pictorial Table of Cartesian Commentators on the Objective Reality Contents of Secondary Quality Sensations.”

Why does Nadler’s placement of these two passages seem to support his claim that objective reality is essential to ideas? Descartes first says that the name “idea” is strictly appropriate only for thoughts that are as if images of things. Five pages later, he says that the objective mode of being belongs to ideas by their nature. Read together, those sentences support an essential claim about strict ideas. The further move is to extend that claim to every later broad use of “idea.” That extension, rather than the essential claim within the strict domain, requires justification.

Gary Hatfield explicitly draws a universal conclusion about representation:

“I not only take Descartes at his word when he says that ‘the objective mode of being belongs to ideas by their very nature’ (7: 42), but I also take him to be saying with this phrase that all ideas represent.” (Gary Hatfield , “Descartes on Sensory Representation, Objective Reality, and Material Falsity,” in Descartes’ Meditations: A Critical Guide, ed. Karen Detlefsen , Cambridge: Cambridge University Press, 2012, 144; Descartes passage at AT VII 42; CSM II 29)

Hatfield’s inference requires distinguishing the claim that all ideas represent from the claim that every idea contains objectively real representational content. Whether the former establishes the latter depends on the sense of representation involved. For my argument against treating objective reality as a universal account of thought, see “Condensation: Why Objective Reality Cannot Be Descartes’s Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict Idea Model.”

I reject the universal reading according to which objective reality belongs essentially to every item Descartes calls an idea, so that every conscious mental mode—including every sensation, act of will, and state of fear—must contain objective reality simply in virtue of being an idea in the broad sense. At AT VII 37; CSM II 25, Descartes restricts the proper name “idea” to thoughts that are as if images of things. At AT VII 42; CSM II 29, he says that objective being belongs to ideas by their nature. What does not follow is that the later sentence defines every item Descartes is willing to call an idea, including the immediately perceived forms of willing, fearing, sensing, and the common notions.

The commentators’ claims quoted above must nevertheless be distinguished. Nadler explicitly appeals to Descartes’s strict use of “idea” for thoughts that are as if images of things. His claim that objective reality is a defining feature of ideas can therefore be read as applying to strict ideas, which is consistent with the interpretation I defend. To establish the universal thesis, he would also need to show that every broad-sense idea—including immediately experienced sensations, volitions, and passions—contains objectively real representational content.

Smith’s statement that ideas possess objective reality by their very nature raises the same question about scope. If he means strict ideas, I agree; if he means everything Descartes calls an idea, the broader claim requires an argument. The assertion that objective reality belongs essentially to ideas does not settle which sense of “idea” governs that assertion.

Hatfield takes a further step by interpreting Descartes’s sentence as saying that all ideas represent. But that conclusion requires clarification: does every idea contain an objectively real representation, or can some ideas represent in another sense, such as a sensation’s functioning as a natural sign of its bodily cause? I call the latter external representation and distinguish it from internal representation possessing objective reality. Only the former interpretation attributes objective reality to every broad-sense idea. Establishing that every idea represents in some sense would not, by itself, establish that every idea contains objectively real representational content.

I challenge the inference from objective reality’s belonging by nature to strict ideas to its belonging to every thought Descartes calls an idea. The sentence under discussion occurs within the causal argument, where ideas are being compared according to the objective reality of what they represent. I first argue that the passage does not justify extending the claim to every Cartesian idea, and then argue that Descartes’s broader use of “idea” provides independent counterexamples to the universal thesis.

Descartes’s “by their very nature” sentence must be read in its argumentative context. He is not there giving a maximally broad definition of idea. He is developing the causal argument for God’s existence, and that argument turns on the objective reality contained in ideas insofar as they represent different things. The relevant domain is therefore not every conscious mental mode, but ideas under objective consideration: strict ideas whose represented contents enter the causal hierarchy of modes, finite substances, and infinite substance. A true and immutable nature, such as triangularity, can be represented without an externally existing instance, but it does not introduce a fourth degree into that hierarchy.

Two distinct claims are in play. Confusing them obscures the entire dispute. The first is a claim about what the text licenses, hereafter Claim 1: the “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea. When Descartes writes that this objective mode of being belongs to ideas by their very nature, the word “ideas” stands without any qualifier, and the universalist takes it to range over every item Descartes anywhere calls an idea. My first claim denies that the passage supplies that range. Read in its place in the causal argument, “ideas” picks out the ideas already under discussion, namely those considered insofar as one represents one thing and another another. This supports a positive interpretation of the passage’s restricted scope. It does not yet refute the universal thesis, because whether every broad idea also contains objective reality remains a separate question.

The second claim, hereafter Claim 2 (The universal-objective-reality thesis is false: some broad-sense ideas contain no OR-bearing representational content), is stronger and independent: the universal-objective-reality thesis is false because some broad-sense ideas contain no OR-bearing representational content. It holds that the unrestricted thesis is not merely unsupported but false. A single secure counterexample would suffice logically, but the interpretive burden is to establish one without presupposing the restriction thesis. The cases below face different objections and must be argued separately. Some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation, provide three distinct challenges to universal objective reality. The idea of nothing requires qualification because Descartes says it can scarcely be called an idea. In a cold sensation, phenomenal coolness is a formally real quality of the sensory mode. The sensation externally represents the particular configurations of matter in motion that cause it by functioning as a natural sign, but it does not thereby contain an objectively real internal representation of those configurations.

The Third Meditation supports Claim 1 (The “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea) through three connected passages. Descartes restricts the proper name “idea” to thoughts that are as if images of things (AT VII 37; CSM II 25); quatenus [insofar as] marks the respect in which ideas represent different things (AT VII 40; CSM II 27–28); and iste [this] points back to the objective mode of being already under discussion (AT VII 42; CSM II 29). They support the restricted reading without independently supplying a proof that the strict and broad extensions differ. My independent case against the unrestricted thesis rests on separate arguments concerning some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation. The Conversation with Burman supplies evidence relevant to the first two cases; the sensory case requires its own textual analysis.

The better interpretation preserves the full force of Descartes’s language while restricting its scope. Objective reality does belong to ideas by their very nature when “idea” is taken strictly. It does not follow that every broad idea contains objective reality. The difference is not merely a verbal distinction imposed on Descartes. It is grounded in Descartes’s taxonomy of thoughts in the Third Meditation, in his later broad definitions of “idea,” in the strict/broad distinction attributed to him in the Conversation with Burman, and in the treatment of sensations and material falsity.

The Third Meditation First Restricts the Proper Name “Idea”

The decisive textual point occurs before the “by their very nature” sentence. Descartes begins the relevant stretch of the Third Meditation by dividing thoughts into kinds. Some thoughts are image-like or representation-like. Others include additional forms. His initial description of the first class is: “Quædam ex his tanquam rerum imagines sunt.” [Some of these are as if images of things.] (AT VII 37; CSM II 25)

He then adds the crucial restriction: “quibus solis proprie convenit ideae nomen.” [To which alone the name idea properly belongs.] (AT VII 37; CSM II 25)

What should govern the reading of the later passage? This phrase supplies the starting point. Descartes has not yet licensed a universal thesis about every conscious mode. He has said that the name “idea” properly belongs only to those thoughts that are as if images of things. These are strict ideas. They are the thoughts that can function in the causal proof because they can be considered according to what they exhibit objectively.

Descartes immediately distinguishes this class from thoughts that have something more than the likeness of a thing: “Aliae verò alias quasdam praeterea formas habent.” [But others have certain other forms in addition.] (AT VII 37; CSM II 25)

His examples are willing, fearing, affirming, and denying. Descartes says of such cases: “aliquid etiam amplius quàm istius rei similitudinem cogitatione complector.” [I also include in thought something more than the likeness of that thing.] (AT VII 37; CSM II 26)

He also says of this second class: “semper quidem aliquam rem ut subjectum meae cogitationis apprehendo.” [I always apprehend some thing as the object of my thought.] (AT VII 37; CSM II 26)

The force of semper [always, in every such case] must be determined by the class of thoughts Descartes is describing. His taxonomy, or classification of thoughts, identifies willing, fearing, affirming, and denying as thoughts with additional forms. In each such case, I apprehend something as the object of my thought and include in that thought something more than the likeness of the thing. The passage therefore presents a challenge to the restriction I defend, but it does not establish that every conscious mode contains objectively real representational content. Its immediate claim concerns the thoughts specified in this part of the classification. (AT VII 37; CSM II 25–26)

I understand a fear of a lion as one occurrent mental mode considered in two respects. It represents the lion through objectively real representational content, and it has the formally real affective character of fear. The broad-sense idea is the fear of the lion itself. The lion is objectively represented in that thought; the thought’s fearful character is undergone without thereby becoming another objectively represented item. Distinguishing these respects does not divide the thought into two mental modes.

This is an aspectual analysis: representation and affective character are different respects of one thought. The compositional alternative at issue would instead analyze the fear as comprising two numerically distinct mental modes, an idea representing the lion and an affective mode of fearing it. I favor the aspectual reading because Descartes attributes the additional forms to the thoughts themselves. His description permits the thought that represents the lion to be the very thought that is fear. The grammar supports this interpretation, although it does not conclusively exclude every account in terms of distinct constituents. (AT VII 37; CSM II 25–26)

A distinction between first perceiving a lion and subsequently fearing it does not decide between these analyses. That sequence concerns how the fear arises. The aspectual analysis concerns the resulting fear itself. An earlier perception may occasion the fear without constituting a separate representational mode within it. Whether that perception ceases or continues, I understand the fear of the lion as one thought with both representational and affective character.

Likewise, I understand an affirmation that God exists as one thought that represents God and has the judicative character of affirmation. Insofar as it represents God, the thought contains infinite objective reality; its being an affirmation does not thereby supply another objectively represented item. These examples clarify where objective reality belongs within a thought. They do not themselves refute the universal thesis, since both the fear of the lion and the affirmation that God exists contain objectively real representational content. My argument against universal objective reality requires independently defended cases of broad ideas that lack such content, and it does not depend on excluding every compositional analysis.

The passage also leaves open the later case of secondary-quality sensations, such as a cold sensation. Descartes does not list sensing alongside willing, fearing, affirming, and denying in this sentence. His description of the additional forms therefore cannot simply be extended to sensations without further argument. The Third Meditation and the Fourth Replies examine sensory confusion separately, including the difficulty of determining whether a sensation exhibits anything positive outside itself. Those texts require their own analysis. (AT VII 43–44, 233–35; CSM II 30, 163–64)

A universalist might treat Descartes’s claim about willing and fearing as a general law of consciousness and infer that every sensation must likewise contain an objectively represented item. But the presence of an objectively represented lion in a fear of a lion does not establish that every fear, still less every sensation, contains objective reality. I also defend the possibility of generalized fear in which no object is represented as feared. On my interpretation, this is a formally real affective state containing no objectively real representational content. The proposed case is not merely fear of an unidentified threat; it is fear without an objectively represented object.

Such generalized fear must also be distinguished from a reflective idea that represents the fear itself. On my interpretation, immediately experiencing fear does not require making that fear the object of another thought. A reflective idea of the fear would contain objectively real representational content corresponding to a mental mode, but this does not establish that the fear being reflected upon already contains such content. I develop this distinction in “Why Objective Reality Cannot Be Universal In Descartes’s Theory Of Ideas: Nothing, Eternal Truths, Sensations, And Fear With Claude Opus 4.6.”

Descartes’s use of semper [always, in every such case] remains a textual challenge to this account. (AT VII 37; CSM II 25–26) I therefore distinguish the object-directed fears described in the passage from the generalized fear whose possibility I defend. A fear of a lion contains an objectively real representation of the lion. But this example does not settle whether fear can also occur without any objectively represented object. To defend that further possibility, I must explain how generalized fear can be an immediately experienced mental state without representing either something feared or the fear itself. The universalist, conversely, must explain why such a state necessarily contains objectively real representational content. The issue is whether every fear state must contain some objectively real representational content, or whether fear can occur without any such content.

I discuss generalized fear here to clarify the limits of the taxonomy argument and refer elsewhere for its fuller defense. The three counterexamples developed separately below concern some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation. Their force does not depend on accepting the proposed case of generalized fear.

The governing question is therefore which content within a cognition, if any, is OR-bearing. An aspectual analysis helps formulate that question without deciding its answer in advance. Where a thought represents a mode, a finite substance, or an infinite substance, its objective reality corresponds to what is represented. A true and immutable nature, such as triangularity, can also be represented without requiring an externally existing instance; it does not introduce a separate degree into the hierarchy of modes and substances. The presence of such representational content must be established for the thought under consideration.

On the interpretation I defend, secondary-quality sensations, such as a cold sensation, present positive phenomenal content without containing an objectively real representation of a corresponding external quality. Phenomenal coolness is a formally real qualitative determination of the sensory mode. Its occurrence does not make it an objectively represented item within that sensation.⁵ For extensive defense of the claim that secondary-quality sensations lack objective reality, see the following DTOI posts:
“ Convincing ChatGPT 4.0 (April 2023 version) that Cartesian secondary quality sensations (SQS) have no objectively real mental content”
“Proving that cold sensations do not have any objective reality to Bing’s Copilot with ChatGPT 4”
“ScholarGPT (January 2025) asserts independently that a cold sensation lacks objective reality”
“ChatGPT 4.5 (February 2025) defends material false sensations lack objectively real representational content”
“Proving sensations are ideas with no objective reality to ScholarGPT”

The sensation may nevertheless externally represent its bodily cause by functioning as a natural sign. Such lawful signification must be distinguished from an internal representation in which a determinate extra-sensory representatum [item represented] possesses objective being. The argument for this interpretation depends on the account of sensation developed below, rather than on the taxonomy at AT VII 37; CSM II 25–26 alone.

Other cases concern intelligible principles or negative thought. Some common notions, on my interpretation, entirely lack objectively real representational content, while others contain it; necessity or generality alone does not decide the issue. The idea of nothing likewise requires its own analysis. These cases must be distinguished from a fear of a lion, which does contain objective reality through its representation of the lion. The absence of objective reality from a thought’s affective character does not establish its absence from the thought as a whole.

I take the requirement that ideas are as if of things to govern ideas properly and strictly so called. Thoughts falling outside that strict representational class bear on the separate universalist thesis that every item Descartes calls an idea must contain objectively real representational content. The strict and broad uses reported in the Conversation with Burman support distinguishing these questions. Merely calling a thought an idea does not determine which use applies or establish that it contains objective reality. (AT V 153; CSMK III 338)⁶For the wider textual basis of the broad use, see my “Strict and Broad Ideas in DTOI.”

The initial taxonomy thus supplies a reason against assuming an unrestricted reading. I read Descartes’s later attribution of objective being to ideas by their nature in continuity with his earlier restriction of the proper name to thoughts that are as if images of things. The universal-objective-reality reading must justify extending that attribution to every broad-sense idea. The taxonomy alone does not refute the extension, but neither does the unqualified occurrence of the word “ideas” establish it.

The Objective-Reality Argument Depends on an “Insofar As” Restriction

Next consider Descartes’s quatenus [insofar as] distinction.⁷In both clauses, quatenus [insofar as] tells us how Descartes is considering the same ideas. First, he considers them simply as acts of thinking: each idea is a finite mental mode. Second, he considers what those ideas represent: an idea of a finite substance and an idea of God differ in objective reality because they represent things of different degrees of reality. These are two ways of considering the same ideas. The distinction does not divide them into two groups or require each idea to consist of two separate mental modes. The second clause concerns ideas that represent one thing rather than another; it should not be generalized into the separate thesis that every broad-sense cognition necessarily has an OR-bearing representational aspect.
He first considers ideas “quatenus ideae istae cogitandi quidam modi tantùm sunt.” [Insofar as those ideas are merely certain modes of thinking.] (AT VII 40; CSM II 27) He then introduces the contrasting representational description: “quatenus una unam rem, alia aliam repraesentat.” [Insofar as one represents one thing, another another.] (AT VII 40; CSM II 28)

This distinction is decisive for the ideas already within the representational comparison. Considered merely in respect of their formal reality, each is a finite mode of thought. Their different degrees of objective reality enter the comparison when those ideas are considered insofar as they represent different things. The causal proof needs exactly that second description. It needs the idea of a mode, the idea of a finite substance, and the idea of God to differ according to the objective reality of what they represent. What the passage does not establish is that every conscious mental modification must therefore contain an OR-bearing internal representation.

Why read the “by their very nature” sentence within the same restricted comparison? The answer can be stated in five steps. These are not five independent proofs. They trace the continuous argumentative sequence in which the sentence at AT VII 42; CSM II 29 occurs:

1. At AT VII 40; CSM II 27–28, Descartes distinguishes ideas considered as modes of thought from ideas considered as representing one thing rather than another. The first quatenus [insofar as] is not a denial that the ideas then under comparison represent. It is a restriction of the comparison. Considered merely as modes inhering in the mind, the ideas do not differ in a way the causal argument can use. Each is a finite mode of thought. If the argument stopped there, there would be no hierarchy to explain and no need for a cause proportioned to different degrees of objective reality.

2. Objective reality enters under the second aspect. The inequality required by the causal argument is determined by what the ideas represent: modes, finite substances, and infinite substance. Ideas that represent substances contain more objective reality than those that represent merely modes or accidents. (AT VII 40; CSM II 28) The difference is not a difference in consciousness, vividness, or formal reality. It is a difference in the ontological rank of what is represented. That is already a restriction of subject matter. The ideas in play are ideas for which the question of represented rank has already arisen.

3. The discussion then continues specifically with an idea’s containing this rather than that objective reality, and with the demand for a cause containing at least as much reality formally or eminently as the idea contains objectively. The argumentative context is already representationally restricted. Descartes is not asking how a thought can be conscious, or how a volition can be immediately perceived. He is asking how an idea can contain a given degree of objective reality, and why that degree cannot come from nothing. The subsequent attribution of an objective mode of being to ideas by their nature answers that causal question. Its role supports continuity with the represented contents already under discussion, although causal function alone does not settle the extension of “ideas.”

4. Descartes says not merely modus essendi objectivus [objective mode of being], but iste modus essendi objectivus [this objective mode of being]. (AT VII 42; CSM II 29) In this sequence the demonstrative points back to the objective mode already under discussion: the mode by which what is represented is objectively in the intellect through an idea. The comparative structure clarifies the sentence’s causal function without excluding its essentialist force: “Nam quemadmodum iste modus essendi objectivus competit ideis ex ipsarum naturâ, ita modus essendi formalis competit idearum causis . . .” [For just as this objective mode of being belongs to ideas from their own nature, so the formal mode of being belongs to the causes of ideas . . .] (AT VII 42; CSM II 29) The quemadmodum / ita [just as / so] structure pairs two modes of being in order to block a mistake about causes: one must not suppose that because the reality in the idea is only objective, the cause need contain that reality only objectively. The sentence is doing causal work, but a sentence can perform that work while also expressing an essential claim. Likewise, the backward reference of iste [this] establishes continuity of subject matter without by itself restricting the extension of ideis [to ideas]. A universalist can agree that “this” refers back to the objective mode of being already discussed while still arguing that Descartes means all ideas. The case for restricted scope therefore rests on the earlier taxonomy together with the continuing comparison of represented contents, not on the demonstrative alone.⁸The essential wording at AT VII 42; CSM II 29 does not by itself determine whether “ideas” ranges over every item Descartes calls an idea or over the ideas already under representational comparison. Nor does it establish that some Cartesian ideas lack objective reality. The unrestricted inference requires an additional premise identifying the operative sense with the broadest Cartesian use. My contextual argument supports the restricted interpretation. The independent case against the universal thesis comes from separate arguments concerning some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation. Each case is examined on its own grounds.

5. Descartes then describes the relevant ideas as veluti quasdam imagines [like certain images]. (AT VII 42; CSM II 29) This returns the discussion to the characterization introduced at AT VII 37; CSM II 25: thoughts that are as if images of things and to which the name “idea” properly belongs. An idea can fall short of the reality of its adequate cause, but it cannot contain more reality objectively than that cause contains formally or eminently. The comparison makes sense within the representational domain whose contents are being ranked. It does not establish a thesis about every immediately perceived form of thought.

What does this sequence establish? Its conclusion must be limited to what the five steps warrant. They support Claim 1: the “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea. This is a positive interpretation of the sentence in its argumentative context. It is not yet a proof that some ideas lack objective reality. The sequence identifies the operative comparison in which one idea represents one thing and another another. Extending the attribution to every item Descartes calls an idea requires an additional justification for the broader scope. Neither the demonstrative nor the causal function of the sentence independently settles that question.

The structure of the causal proof reinforces this reading of the operative comparison. Descartes writes: “in quo omnis realitas formaliter contineatur, quae est in ideâ tantùm objective.” [In which all the reality is contained formally that is in the idea only objectively.] (AT VII 42; CSM II 29)

This is a causal adequacy principle applied to objective reality in ideas. The idea contains the relevant reality objectively; its adequate cause must contain at least that much reality formally or eminently. The proof works because represented contents can differ in objective-reality rank. It does not require the further premise that every conscious mode contains OR merely because it is conscious.

The universal-objective-reality reading therefore extends a claim about the causal requirements of represented content into a thesis about all occurrent thought. My interpretation preserves the argument’s immediate point: represented content possesses objective being and requires a cause adequate to its degree of objective reality. Whether every broad-sense idea contains such content remains the separate question addressed by Claim 2.

“By Their Very Nature” Should Not Be Weakened, but Its Scope Must Be Restricted

Descartes does not say that objective being merely happens to accompany some ideas. He says it belongs to ideas by their nature. That is a strong claim, and it should be retained. A strict idea does not first exist as a purely formal mental event and then contingently acquire objective being from an additional act. To be a strict idea is to be a mental mode whose represented content possesses objective being in the intellect.

But a strong claim within a restricted domain is not a universal claim over every broader use of a term. The issue is scope. Descartes’s sentence is true of ideas insofar as they are strict representational ideas. It does not follow that it is true of everything called an idea when “idea” is taken broadly for the immediately perceived form of any thought.

This is the central logical point. From the claim that objective reality belongs by nature to ideas in the relevant strict sense, it does not follow that objectively real representational content belongs to every Cartesian idea in every sense of “idea.” Nor does it follow that every conscious mode contains an OR-bearing internal representation. The unrestricted inference moves from the strict use governing the causal comparison to the broader use governing immediately perceived thoughts without establishing that the attribution extends to both. The same word does not guarantee the same quantifier domain.

What is the universalist’s strongest compact reply? If objective being belongs to ideas by their nature, why not infer that anything lacking objective being is, by that fact, not an idea in the sense of the sentence? This reply does not require ignoring the restriction of the proper name at AT VII 37; CSM II 25, or weakening the essential force of the later claim. The inference is a contraposition, not a conversion. From the premise that every idea in the operative sense possesses objective being, it validly follows that anything lacking objective being is not an idea in that same sense. If the proposed counterexamples lack objective reality, the universalist may therefore exclude them from the strict class. But exclusion from that class does not exclude them from every Cartesian use of “idea.”

The logical operation is valid; the disputed move is a change in the sense of “idea.” From the claim that every strict idea has objective reality, contraposition yields only that a thought lacking objective reality is not a strict idea. No biconditional is required. The restriction thesis accepts that result. What does not follow is that a thought which fails the strict test is not an idea in any sense Descartes recognizes. The Second Replies, the Third Replies, and the Conversation with Burman supply evidence for the broader use: an idea may also be the immediately perceived form of a thought. The essential claim at AT VII 42; CSM II 29 does not license excluding from every broader Cartesian use of “idea” whatever fails the strict representational test.

The governing question concerns the idea under examination, not merely the larger episode in which it occurs: which content within the cognition, if any, is OR-bearing? Objective reality in an accompanying strict idea does not thereby belong to another idea associated with it. That issue is distinct from determining which aspects of one cognition possess objective reality. A broad cognition may contain representational content together with volitional, affective, judicative, or sensory character. On an aspectual analysis, these can be different respects of one unified cognition; on a compositional analysis, the relevant episode may instead contain numerically distinct mental modes. The restriction thesis does not depend on settling that question. On either model, objective reality must be established through the presence of objectively real representational content.

Thus the most precise thesis is not simply that only strict ideas have OR, if that is heard as a classification of whole mental episodes into mutually exclusive classes. The better thesis is content-sensitive: objective reality belongs by nature to strict representational content within cognition. Broad thoughts may be OR-bearing with respect to represented content without their volitional, affective, judicative, or sensory character thereby being objectively represented. My stronger claim is that some broad thoughts contain no objectively real representational content at all. That claim requires the independent arguments developed below.

Descartes Uses a Broad Definition of Idea Based on Immediate Awareness

The strict use of an idea in the Third Meditation is not Descartes’s only use. Numerous times Descartes characterizes ideas in a broad sense with wide applications:

“I use the word ‘idea’ to mean everything that can be in our thought. And I distinguish three kinds.” (Letter to Mersenne, 16 June 1641, AT III 383, CSMK III 183; bold not in origiinal)

“; by ‘idea’ I mean in general everything that is in our mind when we conceive something, no matter how we conceive it.” (Letter to Mersenne, July 1641, AT III 393, CSMK III 185; bold not in original)

“But I make it quite clear in several places throughout the book, and in this passage in particular, that I am taking the word ‘idea’ to refer to whatever is immediately perceived by the mind. For example, when I want something, or am afraid of something, I simultaneously perceive that I want, or am afraid; and this is why I count volition and fear among my ideas.” (Third Replies: AT VII 181; CSM II 127; bold not in original)

“Idea. I understand this term to mean the form of any given thought, immediate perception of which makes me aware of the thought.” (Second Replies, AT VII 160–61; CSM II 113; bold not in original)

“Confused ideas which are made up at will by the mind, such as the ideas of false gods, do not provide as much scope for error as the confused ideas arriving from the senses, such as the ideas of colour and cold (if it is true, as I have said, that these ideas do not represent anything real).” (AT VII 234; CSM II 163)

There is no question here that Descartes labels sensations as ideas. A sensation of cold counts as an “idea” in this broad sense even were it to lack any objectively real content.

As we saw above, in the Second Replies, Descartes gives a broad definition of idea: “Ideae nomine intelligo cujuslibet cogitationis formam illam.” [By the name idea I understand that form of any thought.] (AT VII 160; CSM II 113)

He immediately explains the consciousness condition: “per cujus immediatam perceptionem ipsius ejusdem cogitationis conscius sum.” [By whose immediate perception I am conscious of that very thought.] (AT VII 160; CSM II 113)

This definition identifies an idea with the form of any thought by whose immediate perception one is conscious of that thought. Its stated criterion is immediate awareness. It does not itself rank represented contents according to their objective reality, as the causal proof does. On the interpretation defended here, this provides a broader use of “idea” than the strict use governing that representational comparison.

The definition supplies a criterion of ideahood distinct from possession of objective reality: immediate awareness of the thought. That distinction does not by itself prove that the strict and broad uses differ in extension. A universalist may maintain that every immediately perceived thought also contains represented content. The point established here is narrower: the definition does not make objective reality the stated ground of broad ideahood. Whether some broad ideas lack OR must be established by independent cases. Equally, broad ideahood does not entail absence of objective reality: a fear of a lion can contain OR-bearing content representing the lion without its affective fear character becoming another represented item.

This also avoids a regress. If every conscious thought required a further, numerically distinct strict idea representing it in order to be conscious, that further idea would require another such idea, and so on. On my interpretation, Descartes avoids this regress because occurrent thoughts are directly and immediately perceived. Immediate perception does not by itself establish that a thought contains OR representing itself. The fear can be a conscious fear without containing, in itself, the objective reality of fear-as-object. A reflective idea of fear may represent fear as a mental mode and have mode-level objective reality. But that does not show that the original fear was already an internal representation of itself.

But what represents the lion, granting that the fear does not represent itself? Two analyses are available. On the aspectual analysis, one occurrent thought is fear and represents the lion, and these are two respects under which the single thought is considered. On a compositional analysis, the episode contains a strict idea of the lion, which bears objective reality, together with a distinct affective mode of fear. The two analyses agree on the point relevant here: the presence of OR-bearing content representing the lion does not make the fear character itself OR-bearing. They differ about the internal architecture of the episode.

The aspectual analysis has substantial textual support. Descartes’s own division at AT VII 37; CSM II 25 is not expressed as a division between representations and separate accompaniments of representations. It is a division between thoughts that are as if images of things and thoughts that have certain other forms in addition, where the additional form is predicated of the same thought that includes the likeness: when I will or fear, he says, I include in thought something more than the likeness of the thing. That grammar naturally supports an aspectual reading of one thought under different respects, although it need not settle the metaphysics of the episode against every compositional alternative. The Third Replies (AT VII 181; CSM II 127–28) strengthen the point relevant to the present argument, since Descartes there counts willing and fearing as ideas themselves on the ground that they are immediately perceived.

The Third Replies Explain Why Volition and Fear Qualify as Broad Ideas

The same broad usage appears in the Third Replies. Descartes explains that he uses the name “idea” for everything immediately perceived by the mind: “nomen ideae sumere pro omni eo quod immediate a mente percipitur.” [To use the name idea for everything that is immediately perceived by the mind.] (AT VII 181; CSM II 127–28)

Descartes then explicitly includes volition and fear themselves among ideas because he immediately perceives his willing and fearing: “cùm volo & timeo, quia simul percipio me velle & timere, ipsa volitio & timor inter ideas a me numerentur.” [When I will and fear, because I simultaneously perceive that I will and fear, volition and fear themselves are counted by me among ideas.] (AT VII 181; CSM II 127–28)

What does the passage prove? It confirms the ground of the broad use without independently refuting universal objective reality. Volition and fear count as ideas because they are immediately perceived, not because their volitional and affective characters are assigned an objective degree. They may nevertheless contain OR-bearing content with respect to what is willed or feared. The distinction is between the reason a thought qualifies as a broad idea and the represented content, if any, through which the cognition possesses objective reality. For the fuller taxonomy, see my “Strict and Broad Ideas in DTOI.”

Three Cases, and What Each Can Show

Claim 2—The universal-objective-reality thesis is false: some broad-sense ideas contain no OR-bearing representational content—is supported here by three separately argued cases. Each answers a different universalist reply, and the reply available in one case does not transfer automatically to the others. Some common notions supply the first case through an account of intelligible logical content without an internally represented nature. The idea of nothing supplies a second case through an account of negative thought without a positive representatum [item represented]. Secondary-quality sensations, such as a cold sensation, supply the third: on my interpretation, their positive phenomenal content occurs formally without being objectively represented in the sensation. The generalized fear discussed earlier clarifies the issue raised by the taxonomy; the three cases developed below carry the independent argument in this article.

Case	Textual basis	Counterexample defended here	What the argument must establish
Some common notions	Ideas “taken more broadly,” not properly ideas of things (AT V 153; CSMK III 338)	The principle of noncontradiction articulates a logical exclusion without internally representing a nature or other OR-bearing item	Why the thought entirely lacks objective reality; its generality, necessity, and classification as a broad idea do not alone establish that result
Idea of nothing	“Only negative” and “scarcely” an idea, followed by the restriction to the proper and strict use (AT V 153; CSMK III 338)	A negative thought without a positive OR-bearing representatum [item represented]	Why it qualifies as a broad idea and why conceptual dependence on an understanding of being need not place an objectively real representation of a positive item within the negative thought
Secondary-quality sensations, such as a cold sensation	The discussions of sensory obscurity and material falsity (AT VII 43–44, 233–35; CSM II 30, 163–64)	Phenomenal coolness is formally present without being objectively represented, while the sensation can function as a natural sign of its bodily cause	Why the sensation itself lacks objective reality; uncertainty about what it exhibits outside itself does not alone prove that absence, and external signification must be distinguished from internal representation

Strict and Broad Ideas in the Conversation with Burman

I take the exchange reported in the Conversation with Burman as explicit evidence that Descartes distinguished strict and broad uses of “idea.” Its significance extends beyond terminology: the conditions governing strict ideas cannot simply be assumed to govern every thought Descartes calls an idea. Frans Burman (1628–1679) raises the idea of nothing against the claim that ideas can only be as if of things.

The reply recorded in the exchange is explicit: “Illa idea est solùm negativa, et vix vocari potest idea; auctor autem hîc sumit ideam proprie et stricte.” [That idea is only negative and can scarcely be called an idea; the author, however, takes idea here properly and strictly.] (AT V 153; CSMK III 338)⁹Translations from the Latin in this section are mine. The CSMK references identify the corresponding passages.

The reply then introduces common notions: “Aliæ etiam dantur ideæ notionum communium, quæ non sunt ideæ rerum proprie; sed tum idea latius sumitur.” [There are also ideas of common notions, which are not properly ideas of things; but then idea is taken more broadly.] (AT V 153; CSMK III 338; bold and italic not in original) These remarks distinguish two cases in which the strict conditions for being an idea cannot simply be assumed to govern every use of the term: the negative thought of nothing and the ideas of some common notions.

For Claim 1 (The “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea), I draw a limited conclusion from this exchange. The contextual qualification hîc [here] concerns the passage Burman raises, not the “by their very nature” sentence at AT VII 42; CSM II 29. The report therefore does not independently determine the scope of that sentence. It does, however, defeat the presumption that an unqualified occurrence of “ideas” must include everything Descartes elsewhere calls an idea. My argument for restricted scope still rests on the Third Meditation sequence examined above. Burman supplies evidence that the distinction on which that argument relies belongs to Descartes’s own reported usage.

For Claim 2, I argue that some common notions and the idea of nothing supply two counterexamples to the universal attribution of objective reality. Secondary-quality sensations, such as a cold sensation, supply the third, which I examine in the next section. I give each case a separate argument. Their inclusion under the broad use of “idea” establishes their relevance to the universalist’s domain; it does not, by itself, establish that they lack objectively real representational content.

My argument concerning common notions is selective. In Principles I.48–49, Descartes distinguishes things and their affections from eternal truths, including the principles that nothing comes from nothing and that the same thing cannot both be and not be at the same time (AT VIIIA 22–24; CSM I 208–9). I do not infer that every common notion lacks objective reality merely because it is an eternal truth or qualifies as an idea in the broad sense. Those classifications leave open whether the thought contains objectively real representational content.

The contrast I defend is between common notions that entirely lack objective reality and those that contain it. On my interpretation, the principle that the same thing cannot both be and not be at the same time contains no OR-bearing representatum [item represented]. By contrast, in understanding that a triangle has three sides, I represent triangularity, a true and immutable nature of a possible mode of extension. That geometrical thought contains objective reality.¹⁰I use “common notion” here broadly enough to include self-evident geometrical truths. Descartes discusses the representational use of the idea of a triangle in Principles I.59 (AT VIIIA 27–28; CSM I 212–13) and its true and immutable nature in the Fifth Meditation (AT VII 64; CSM II 44–45). These passages support the triangle example’s representational character; I do not attribute to Descartes an explicit classification of this particular proposition as a common notion.

The reason for denying objective reality to the first thought requires more than observing that it represents no particular object. An idea can represent triangularity without representing any particular triangle. I instead understand the principle of noncontradiction as excluding the joint truth of an existence claim and its negation concerning the same subject at the same time. Its reference to the same subject and time fixes the conditions of that exclusion; it need not present a substance, a temporal mode, or a nature as an object of thought. On this account, the intellect grasps the exclusion itself without internally representing an item to which the objective-reality hierarchy assigns a rank.

A universalist may object that the truth itself, or the incompatibility it expresses, is precisely the represented item. This proposal must explain both what is objectively represented and how its objective reality falls within Descartes’s causal argument. The hierarchy distinguishes the reality of represented modes, finite substances, and infinite substance (AT VII 40–42; CSM II 27–29). Merely calling a logical requirement an object does not establish that it possesses the objective being characteristic of a strict idea. My interpretation instead explains the principle through the exclusion it articulates, without treating that exclusion as an internally represented substance, attribute, mode, or nature. The triangle case shows why generality and necessity cannot decide the issue: a necessary geometrical truth can contain objective reality. The question is whether understanding the principle of noncontradiction likewise involves the internal representation of a Cartesian item.

Nor does the formal reality of apprehending the axiom supply it with objective reality. Performing an intellectual operation is not thereby representing that operation. The apprehension is an actual mental mode, but performing that operation does not thereby make it the object represented. A reflective thought about the apprehension could represent a mental mode; that possibility does not establish such a representation within the original thought. I therefore defend the common-notion counterexample through an account of what the thought does, rather than through the universalist’s failure to name an object.¹¹I develop this argument in “Why Objective Reality Cannot Be Descartes’s Universal Theory of Thought: Burman, Common Notions, and the Collapse of the Strict-Idea Model” and “Do Cartesian Universals Have Objective Reality? Genus, Species, and the Modes of Thinking without Representata” [items represented]. The latter distinguishes ideas that represent natures from notions that perform logical, comparative, or classificatory functions.

Applying a common notion to a represented thing does not establish that the general principle itself contains objective reality. For example, reasoning that a particular lion cannot both exist and not exist at the same time may involve an objectively real representation of that lion. The general principle of noncontradiction, however, does not require that particular representation. My claim that the principle entirely lacks objective reality concerns the principle itself, not every thought in which it is applied. Conversely, the absence of objective reality from the principle would not remove the objectively real representation of the lion from an application that contains it.¹²For the distinction between a principle and the represented things involved in its application, see “Condensation: Why Objective Reality Cannot Be Descartes’s Theory of Thought: Burman, Common Notions, and the Failure of the Strict Idea Model.”

The idea of nothing supplies a distinct counterexample. Here the first objection concerns its membership in the class of ideas: if Descartes says it can scarcely be called an idea, the universalist may try to exclude it altogether. I read the qualification together with the immediately following restriction to the proper and strict use. It explains why the thought does not comfortably bear the strict name; it does not deny that the thought occurs or that it qualifies under the broader criterion of immediate awareness. That criterion is independently supplied by the Second Replies (AT VII 160; CSM II 113) and the Third Replies (AT VII 181; CSM II 127–28). Excluding the thought from the strict class therefore does not answer a thesis that ranges over every broad-sense idea.

My reason for denying objective reality to the thought of nothing is its wholly negative character. I understand it as negating being without presenting a positive nature as its object. This is stronger than the observation that nothing exists outside the mind to answer to the thought: an uninstantiated possible triangle can still be represented with objective reality. Nothing, by contrast, is not a possible object awaiting instantiation or an entity occupying the lowest place in the causal hierarchy. Treating it as such would replace the negation of being with the representation of something.

The nearby discussion in the Conversation with Burman raises a further objection by connecting the understanding of nothing with being (AT V 153; CSMK III 338). I grant that a negative thought can depend conceptually on an understanding of being. But conceptual dependence does not by itself establish that an objectively real representation of a positive item occurs in the negative thought. That further claim requires an argument. On my account, the thought of nothing exercises negation without making either being or the act of negating its represented object. The act has formal reality as a mental occurrence; representing that act would require a different account of what the thought is about.

This counterexample concerns the thought of nothing, rather than every thought involving an absence. Thinking of an absent triangle may contain objective reality because it represents a triangle. Representing an absent triangle supplies no reason to attribute objectively real representational content to the thought of nothing. My claim concerns the complete absence of objective reality from that negative thought.¹³For the distinction between negation, represented privations, and positive sensory content, see my “Privations, Sensations, and Objective Reality: A Closer Look at Arnauld’s Misinterpretation of Descartes’s Ideas.”

What follows from these cases? The argumentative structure is cumulative. For Claim 1 (The “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea), the Conversation with Burman removes the presumption that every unqualified occurrence of “ideas” must include everything Descartes calls an idea in the broad sense. The scope of the “by their very nature” sentence must still be determined from its place in the Third Meditation. For Claim 2 (The universal-objective-reality thesis is false: some broad-sense ideas contain no OR-bearing representational content), I argue that certain common notions and the idea of nothing each supply a counterexample to universal objective reality. Their status as broad ideas establishes their relevance to that thesis; my separate accounts of their logical and negative content explain why, on my interpretation, they lack objectively real representational content. Neither their formal reality as mental occurrences nor the objective reality of other ideas used in applying or explaining them establishes that they themselves contain objective reality. On the interpretation defended here, these cases make the universal thesis false, not merely unlicensed by AT VII 42; CSM II 29. Their force does not depend on accepting the further account of secondary-quality sensations, such as a cold sensation. That third case requires its own argument, which I develop next by distinguishing formally present phenomenal coolness from objectively represented content while preserving the sensation’s function as a natural sign of its bodily cause.

Sensations Show That Presentation Is Not the Same as Objective Reality

Do sensations provide independent support for the same conclusion? They do on the interpretation defended here. In Principles I.66–71, Descartes distinguishes what is clearly contained in a sensation from the further judgment that a resembling quality exists in the body (AT VIIIA 32–36; CSM I 216–19). Sensations, passions, and appetites can be clearly perceived if one does not judge more than what is contained in one’s perception: “Superfunt sensus, affectus, & appetitus, qui quidem etiam clarè percipi possunt.” [There remain sensations, affects, and appetites, which indeed can also be clearly perceived.] (AT VIIIA 32; CSM I 216)

He later marks the crucial difference between considering pain and color merely as sensations or thoughts and judging them to be things outside the mind. His statement that they can be clearly and distinctly perceived applies under the former description: “dolorem quidem & colorem, & reliqua ejusmodi, clarè ac distinctè percipi.” [Pain, color, and the rest of this kind are clearly and distinctly perceived.] (AT VIIIA 33; CSM I 218)

Now consider a cold sensation, a further case of an idea in the broad sense, distinct from Burman’s two cases. The argument requires separating Descartes’s uncertainty about what the sensation exhibits from the positive account of the manner in which its phenomenal character is present. The uncertainty passage does not itself identify objectively real content; the further account of sensory presence supports my conclusion that the sensation itself lacks such content.

Descartes calls the idea materially false “propter hoc tantùm . . . quod, cùm sit obscura & confusa, non possim dijudicare an mihi quid exhibeat quod extra sensum meum sit positivum, necne.” [For this reason only . . . that, since it is obscure and confused, I cannot determine whether it exhibits to me something that is positive outside my sensation, or not.] (AT VII 234; CSM II 163–64) The sensation’s phenomenal positivity is not in question: phenomenal coolness is experienced. What remains undetermined is whether the sensation exhibits something positive outside itself. This distinction does not yet establish whether the sensation contains objective reality.

Phenomenal coolness is not thereby a representatum [item represented] of the cold sensation. This does not mean that phenomenal coolness falls outside Cartesian mental reality or that a mental mode could never itself become an object of representation. It means that, within the cold sensation as such, phenomenal coolness occurs as the formally real qualitative character of the sensation rather than as an item objectively represented by it. The claim concerns its manner of presence within the sensation. It is not an inference from the absence of a resembling quality outside the mind.

The positive conclusion defended here is that the cold sensation itself lacks OR. That conclusion does not follow from the inability to determine whether something positive outside the sensation is exhibited. Epistemic uncertainty alone does not establish the absence of represented content. My argument instead distinguishes what occurs in the sensation from what is represented by it. Phenomenal coolness occurs as its qualitative character; the bodily configurations that cause the sensation are externally signified through its function as a natural sign; and the further construal of coolness as a positive bodily quality belongs to the intellectual uptake. On this account, none of these supplies an objectively real internal representation within the sensation itself. A universalist can dispute this account, but must explain where such represented content enters. Neither the mere occurrence of the sensation nor its causal connection to a body establishes it.

Phenomenal coolness is therefore not excluded because it fails to be a Cartesian mode. On the contrary, as actually occurring in consciousness it belongs to the formal reality of the sensory mode. What excludes it from the objective-reality calculation in this sensation is its manner of presence: it is phenomenally presented, not objectively represented. A formally real mental mode can itself become a representatum [item represented] in another act of thought, but it does not acquire objective reality merely by occurring phenomenally in the sensation.

It is not that the sensation purports to exhibit an external quality and fails. On my interpretation, there is no such internal representational content in the sensation. What the sensation has is vivid phenomenal positivity together with obscurity about what, if anything, it exhibits outside itself. The construal of its phenomenal character as a positive external quality belongs to the further uptake. This account allows the sensation to externally represent its bodily cause as a natural sign. A cold sensation therefore falls outside the strict tanquam rerum imagines [as if images of things] class on the account defended here, but it is not the same kind of case as the idea of nothing or the specified common notions. Nothing is merely negative. The principle of noncontradiction articulates an intelligible logical exclusion. A cold sensation supplies a positive phenomenal basis for error. That is why the sensory case requires its own argument from the Fourth Replies and Principles I.66–71.

The obscurity of the sensation provides the occasion for that further construal: “obscuritas verò, quæ sola mihi dat occasionem judicandi istam ideam sensûs frigoris . . .” [But the obscurity, which alone gives me occasion for judging that idea of the sensation of cold . . .] (AT VII 234–35; CSM II 164) The sensation supplies the positive phenomenal basis for error without, on my interpretation, itself internally representing a positive external quality. The Fourth Replies support distinguishing the sensation’s own positivity from the alleged objective presence of cold. On the supposition that cold is merely a privation, Descartes writes: “si frigus sit tantùm privatio, frigoris idea non est frigus ipsum, prout est objective in intellectu, sed aliud quid quod perperam pro istâ privatione sumitur; nempe est sensus quidam nullum habens esse extra intellectum.” [If cold is only a privation, the idea of cold is not cold itself as it is objectively in the intellect, but something else that is wrongly taken for that privation, namely a certain sensation having no being outside the intellect.] (AT VII 233; CSM II 163) This conditional passage does not by itself prove that the sensation lacks all objective reality. It identifies the positive sensory occurrence that my account distinguishes from an objectively represented item.

Nor does this collapse the idea into a judgment. Descartes forestalls that charge in the same passage: “Nec sane judicium cum ideâ confudi; nam in hac dixi reperiri falsitatem materialem, in illo verò non potest esse nisi formalis.” [Nor indeed have I confused judgment with idea; for I said that material falsity is found in the latter, while in the former there can be none but formal falsity.] (AT VII 233; CSM II 163) The sensation and the uptake are two states within one episode, not an idea replaced by a judgment. Here “uptake” names the further construal without settling whether it is already an act of assent or an apprehension preceding assent. Material falsity remains in the obscure sensory idea; formal falsity belongs to an erroneous judgment. For the full analysis of this two-state structure, see my “Cold Sensation Without Objective Reality: One Episode Or Two States In The S1–D1 Assent Structure Of Descartes’s Theory Of Ideas.”

The lesson is that a sensation can be clearly perceived as a sensory mode without thereby exhibiting an external secondary quality as an OR-bearing representatum [item represented]. Pain, color, heat, and cold are immediately present in consciousness as sensory experiences. But when the mind judges that resembling qualities exist in bodies, it moves beyond what is clearly contained in the sensory perception. Formal error lies in that erroneous judgment. Material falsity remains a feature of the obscure sensory idea that supplies its basis.

If every sensory idea possessed objective reality simply in virtue of being an idea, then the cold sensation would have to contain some OR-bearing representational content independently of the further judgment. The account defended here denies that content to the sensation itself. Mere uncertainty about what corresponds to the sensation in a body is not the ground of that denial. The ground is the account of sensory presentation and external signification as distinct from strict internal representation.

This also explains why sensations can be useful natural signs without containing OR-bearing internal representations. A sensation may be lawfully caused by bodily states and may guide the embodied mind in preserving the mind-body union. But lawful causal connection and practical signification do not by themselves establish objective reality. Objective being is the mode of being that represented content has in the intellect; the mere fact that a sensory state signifies its cause does not establish that the cause is internally represented in that way. A sensory sign can present phenomenal character and occasion judgment without internally representing color, heat, cold, taste, or pain as an external quality. See §4, “Sensations, Signs, and Representation” in my DTOI & Non-DTOI Baselines for AI Models and Anna Ortín Nadal’s “Descartes on Natural Signs and the Case of Sensory Perception,” Journal of Modern Philosophy 6 (2024). Her project supports treating natural signs as a genuine component of Descartes’s theory of sensory perception. The further conclusion that the sensations considered here lack objectively real internal representations requires the separate argument defended in this article.

Material Falsity Does Not Support Universal Objective Reality

Material falsity is often thought to create a problem for the strict-idea restriction. If the relevant Third Meditation ideas are strict tanquam rerum imagines [as if images of things], how can Descartes then introduce ideas that present non-things as if they were things? His phrase is: “cùm non rem tanquam rem repraesentant.” [When they present a non-thing as if a thing.] (AT VII 43; CSM II 30) The immediate purpose of this section is defensive: to show that material falsity does not require abandoning the account of sensations without objective reality defended above. The positive account has already distinguished formally occurring phenomenal character from an item possessing objective being. The question here is whether Descartes’s formulation requires overturning that distinction, or instead marks a case in which phenomenal presentation supplies the occasion for taking what is presented as if it were a thing.

But does repraesentant [they represent or present] itself imply a representatum [item represented], and therefore that the sensation must contain OR-bearing representational content? That is the strongest textual pressure the universalist can apply to this sentence, and it should be answered in stages rather than by a single lexical observation.

The first stage concerns the verb. The objection assumes that repraesentare [to represent or present] must carry the strong sense in which something is internally represented, so that whenever Descartes uses the verb, some represented item must thereby possess objective being in the intellect. But the occurrence of the verb does not by itself establish that conclusion. Descartes can use representational vocabulary in contexts concerned with what is presented or exhibited to the mind, and the philosophical question is precisely what ontological commitment that presentation carries in the particular passage. The lexical possibility of a presentational reading therefore opens the question but does not decide it. Which reading applies at AT VII 43; CSM II 30 must be determined from Descartes’s treatment of the same case.

The second stage is the opponent’s stronger reply. Even if the verb can have a presentational use, non rem tanquam rem [a non-thing as if a thing] might still describe an unsuccessful representational attempt: the idea purports to represent something as a thing although what it purports to represent is not in fact a thing. On such a reading, material falsity would remain a species of representation, and the universalist could argue that some representational content must therefore be present even where its purported object is defective, confused, or nonexistent. Neither confusion nor the absence of an externally existing object is sufficient to exclude objective reality. The grammar of the Third Meditation passage alone does not exclude that interpretation. But neither does it settle the further question whether a positive item is internally represented in the sensation and so possesses objective being of the kind ranked at AT VII 40–42; CSM II 27–29.

The third stage therefore turns to Descartes’s diagnosis when he returns to the same case in the Fourth Replies. Because the idea is obscure and confused, Descartes says that he cannot determine whether it exhibits something positive outside the sensation: “propter hoc tantùm . . . quod, cùm sit obscura & confusa, non possim dijudicare an mihi quid exhibeat quod extra sensum meum sit positivum, necne.” [For this reason only . . . that, since it is obscure and confused, I cannot determine whether it exhibits to me something that is positive outside my sensation, or not.] (AT VII 234; CSM II 163–64) The important point is not that unsuccessful representation is impossible. It is that Descartes does not here identify a determinate positive quality that the sensation represents incorrectly. He leaves open whether anything positive outside the sensation is exhibited at all. That uncertainty does not prove the absence of objective reality, but it prevents treating this passage as itself identifying the positive represented item required by the universalist.

The immediately preceding discussion reinforces that point. On the supposition that cold is merely a privation, Descartes denies that the idea of cold is cold itself objectively in the intellect and identifies what is positively present instead as a sensation: “si frigus sit tantùm privatio, frigoris idea non est frigus ipsum, prout est objective in intellectu, sed aliud quid quod perperam pro istâ privatione sumitur; nempe est sensus quidam nullum habens esse extra intellectum.” [If cold is only a privation, the idea of cold is not cold itself as it is objectively in the intellect, but something else that is wrongly taken for that privation, namely a certain sensation having no being outside the intellect.] (AT VII 233; CSM II 163) This does not by itself prove that the sensation lacks every possible form of objectively real content. It does show that the positive item Descartes identifies in this case is the sensation itself. The passage distinguishes that sensory occurrence from cold itself being objectively in the intellect.

Read in that light, the Third Meditation’s formulation need not say that these ideas contain the objective reality of a non-thing. The phrase tanquam rem [as if a thing] can instead mark the way phenomenal content supplies the basis for subsequently taking what is presented as a positive thing. Phenomenal coolness is positive as a formally real feature of the sensory mode. What does not follow is that the sensation thereby contains an OR-bearing internal representation of a positive quality of cold in bodies. The later text locates the occasion for the taking-as in the obscurity of the sensation: “obscuritas verò, quæ sola mihi dat occasionem judicandi istam ideam sensûs frigoris . . .” [But the obscurity, which alone gives me occasion for judging that idea of the sensation of cold . . .] (AT VII 234–35; CSM II 164) The obscurity occasions the judgment that takes phenomenal cold as indicative of a positive external quality; it does not itself establish an OR-bearing representatum [item represented] already contained in the sensation.

Locating the “as if” partly in the intellectual uptake does not surrender material falsity to the judgment alone. Descartes states that the idea is made materially false “non . . . ab aliquo ente positivo, sed a solâ obscuritate, quæ tamen ens aliquod positivum habet pro subjecto, nempe sensum ipsum.” [Not . . . by some positive being, but by obscurity alone, which nevertheless has some positive being as its subject, namely the sensation itself.] (AT VII 234; CSM II 163–64) Material falsity therefore remains grounded in a feature of the sensory idea itself: its obscurity. The positive subject of that obscurity is the formally real sensation. On my account, the relevant defect is its specific obscurity concerning what, if anything, it exhibits outside itself, together with its positive phenomenal basis for taking it as exhibiting a bodily quality. The idea can supply that basis even when no erroneous judgment is actually made. What this account does not require is an extra-sensory OR-bearing representatum [item represented] corresponding to the supposed positive quality.

This distinction also prevents an equivocation between the formal reality of the sensation and the alleged objective reality of what it presents. The sensation is unquestionably something positive as a mental occurrence. Phenomenal coolness belongs to that formally real sensory mode. But the existence of a positive mental mode does not entail that the mode contains objectively real representational content. Performing or undergoing a sensory modification is not thereby representing that modification, and phenomenally presenting coolness is not thereby objectively representing a positive quality of cold in a body.

What must the universal-objective-reality reading now explain? If every sensory idea possesses objective reality simply in virtue of being an idea, then the materially false cold sensation must contain some OR-bearing representational content independently of the further judgment. The universalist must identify that content, explain what its representatum [item represented] is, and show how its degree of objective reality enters the hierarchy used by the causal proof. The material-falsity passages do not themselves supply those answers. What Descartes expressly identifies as positive in the difficult case is the sensation, while what remains undetermined is whether it exhibits anything positive outside the sensation. My positive argument for the absence of objective reality therefore rests on the account of the sensation’s content already given, rather than on the universalist’s failure to identify an object.

Material falsity therefore does not overturn the distinction between phenomenal presentation and objective representation. On the interpretation defended here, a materially false sensory idea presents positive phenomenal content and, through its obscurity, supplies the basis for taking that content as if it revealed a positive quality outside the mind. Neither the language of presenting a non-thing as a thing nor the positivity of the sensory occurrence establishes an OR-bearing representatum [item represented] within the sensation. The case therefore does not establish that every idea has OR. This defensive result is consistent with, but distinct from, the positive argument already given that the relevant sensory character occurs formally rather than objectively.¹⁴In support, see “What Makes an Idea Materially False in Descartes’s Theory of Ideas?: Why Mere Error-Causation Is Insufficient, Why the Three Main Cases Form an Analogical Unity, and Why Hoffman Mislocates the Relevant Non-Thing with ChatGPT 5.4 Thinking” and “ChatGPT 4.5 (February 2025) defends material false sensations lack objectively real representational content.”

This permits a more exact formulation of the strict-idea thesis. Strict ideas, considered insofar as they genuinely represent something, contain objective reality corresponding to what they represent. The materially false secondary-quality sensations considered here need not therefore be treated as defective strict ideas that somehow possess objective reality of rank zero. On my interpretation, they are broad-sense ideas: formally real sensory modes whose positive phenomenal content is presented without thereby constituting an OR-bearing internal representation. Their obscurity supplies the occasion for the mind to construe what is phenomenally present as being of something outside the sensation. Their function as natural signs preserves external representation of their bodily causes. Neither that signification nor material falsity itself establishes the universal attribution of objective reality.

Conclusions

What has the argument established? Two distinct conclusions about the universal-objective-reality thesis. First, the “by their very nature” claim is restricted to ideas under objective consideration, not every broad-sense idea. The Third Meditation’s taxonomy and the causal comparison support this reading of AT VII 42; CSM II 29. The demonstrative iste [this] maintains continuity with that discussion, but does not independently determine the extension of “ideas.” The attribution of objective being by nature to strict ideas therefore supplies no sufficient ground for extending it to every broad idea. This contextual argument for restricted scope does not itself prove that some broad ideas lack objective reality; that further conclusion requires the independent cases.

Second, the unrestricted thesis is false on the interpretation defended here. The independent arguments identify broad ideas that lack objective reality. Some common notions, of the kind specified in the noncontradiction example, supply one counterexample. The idea of nothing supplies another through its wholly negative character. Secondary-quality sensations, such as a cold sensation, supply a third through the distinction between formally occurring phenomenal character and objectively represented content, while retaining their external signification of bodily causes. Each case requires its own argument. This conclusion is not inferred merely from the failure of the universalist’s reading of AT VII 42; CSM II 29. It rests on the separate analyses of those kinds of thought.¹⁵See also “Condensation: Why Objective Reality Cannot Be Descartes’s Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict Idea Model,” the complete uncondensed version “Why Objective Reality Cannot Be Descartes’s Universal Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict-Idea Model,” and “Why Objective Reality Cannot Be Universal In Descartes’s Theory Of Ideas: Nothing, Eternal Truths, Sensations, And Fear With Claude Opus 4.6.”

The conclusion does not require settling whether every conscious episode includes some accompanying strict idea or whether complex cognition should be analyzed compositionally rather than aspectually. Objective reality belonging to an accompanying strict idea does not thereby belong to the broad idea under examination. Neither accompaniment nor association supplies objective reality to an idea that lacks it. A distinct issue concerns aspects of one cognition: distinguishing those aspects does not by itself establish which possess objective reality. A fear of a lion contains objectively real representational content even though its fearful character is not itself objectively represented. That example therefore supplies no counterexample to universal objective reality. The absence of objective reality in the cases defended here is argued from their respective contents, through the separate accounts of some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation.

Descartes’s statement that objective being belongs to ideas by their very nature should therefore be accepted rather than weakened. Its scope, however, must be supplied by the Third Meditation argument in which it occurs. The ideas under consideration are ideas taken with respect to their representational character, the tanquam rerum imagines [as if images of things] for which differences in objective reality become relevant to the causal proof. The statement that objective being belongs to such ideas by their nature therefore does not establish that every conscious mode Descartes may elsewhere call an idea contains objective reality.

What form should the resulting interpretation take? It must be content-sensitive rather than merely episodic. The governing question is not whether a cognition is called an “idea,” nor even whether some objective reality occurs somewhere within the episode, but which content within the cognition, if any, is OR-bearing? Where a cognition contains a strict internal representation of a representatum [item represented], objective reality belongs to that representational content. Where a cognition instead contains volitional, affective, sensory, negative, or rule-like content without such an internally represented item, its formal reality as a mental occurrence does not by itself generate objective reality. This preserves the causal proof without extending its ontology beyond the representational content to which its ranking structure applies.

That reading also preserves the major textual distinctions developed throughout the argument: the taxonomy of thoughts at AT VII 37; CSM II 25–26, the quatenus [insofar as] contrast at AT VII 40; CSM II 27–28, the demonstrative iste [this, pointing back to the objective mode of being already under discussion] at AT VII 42; CSM II 29, the strict/broad distinction reported in the Conversation with Burman, the treatment of some common notions and the idea of nothing, and the distinction between phenomenal presentation and objective representation in sensation and material falsity. The “by their very nature” passage remains true and important. It does not establish universal objective reality, and the independent counterexamples give a positive reason to reject that universal thesis.

For the underlying taxonomy presupposed throughout, see my “Strict and Broad Ideas in DTOI.”

NOTES

(Hyperlinks below are underlined)

• 1
  The CSM translation reads: “For just as the objective mode of being belongs to ideas by their very nature, so the formal mode of being belongs to the causes of ideas—or at least the first and most important ones—by their very nature.” (AT VII 42; CSM II 29)
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• 2
  See my posts arguing the falsity of the universal readings: “Do Cartesian Sensations Have Objective Reality?: Strict Ideas, Broad Ideas, And Material Falsity In Descartes’s Theory Of Ideas,” “Condensation: Why Objective Reality Cannot Be Descartes’s Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict Idea Model,” its companion piece “Why Objective Reality Cannot Be Universal In Descartes’s Theory Of Ideas: Nothing, Eternal Truths, Sensations, And Fear With Claude Opus 4.6,” and “The Core DTOI Argument: Sensations Without Cartesian Objective Reality.”
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• 3
  Kurt Smith, “Descartes’ Theory of Ideas,” Stanford Encyclopedia of Philosophy, §2, “Ideas and the Formal–Objective Reality Distinction,” third paragraph, and §5, “The Rules: Simple Natures and the Concepts of Clarity and Distinctness,” final paragraph.
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• 4
  Steven Nadler, “The Doctrine of Ideas,” in The Blackwell Guide to Descartes’ Meditations, ed. Stephen Gaukroger (Malden, MA: Blackwell, 2006), 93. For a comparative placement of this reading among other commentators, see my “A Hyperlinked Pictorial Table of Cartesian Commentators on the Objective Reality Contents of Secondary Quality Sensations.”
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• 5
  For extensive defense of the claim that secondary-quality sensations lack objective reality, see the following DTOI posts:
  “ Convincing ChatGPT 4.0 (April 2023 version) that Cartesian secondary quality sensations (SQS) have no objectively real mental content”
  “Proving that cold sensations do not have any objective reality to Bing’s Copilot with ChatGPT 4”
  “ScholarGPT (January 2025) asserts independently that a cold sensation lacks objective reality”
  “ChatGPT 4.5 (February 2025) defends material false sensations lack objectively real representational content”
  “Proving sensations are ideas with no objective reality to ScholarGPT”
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• 6
  For the wider textual basis of the broad use, see my “Strict and Broad Ideas in DTOI.”
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• 7
  In both clauses, quatenus [insofar as] tells us how Descartes is considering the same ideas. First, he considers them simply as acts of thinking: each idea is a finite mental mode. Second, he considers what those ideas represent: an idea of a finite substance and an idea of God differ in objective reality because they represent things of different degrees of reality. These are two ways of considering the same ideas. The distinction does not divide them into two groups or require each idea to consist of two separate mental modes. The second clause concerns ideas that represent one thing rather than another; it should not be generalized into the separate thesis that every broad-sense cognition necessarily has an OR-bearing representational aspect.
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• 8
  The essential wording at AT VII 42; CSM II 29 does not by itself determine whether “ideas” ranges over every item Descartes calls an idea or over the ideas already under representational comparison. Nor does it establish that some Cartesian ideas lack objective reality. The unrestricted inference requires an additional premise identifying the operative sense with the broadest Cartesian use. My contextual argument supports the restricted interpretation. The independent case against the universal thesis comes from separate arguments concerning some common notions, the idea of nothing, and secondary-quality sensations, such as a cold sensation. Each case is examined on its own grounds.
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• 9
  Translations from the Latin in this section are mine. The CSMK references identify the corresponding passages.
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• 10
  I use “common notion” here broadly enough to include self-evident geometrical truths. Descartes discusses the representational use of the idea of a triangle in Principles I.59 (AT VIIIA 27–28; CSM I 212–13) and its true and immutable nature in the Fifth Meditation (AT VII 64; CSM II 44–45). These passages support the triangle example’s representational character; I do not attribute to Descartes an explicit classification of this particular proposition as a common notion.
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• 11
  I develop this argument in “Why Objective Reality Cannot Be Descartes’s Universal Theory of Thought: Burman, Common Notions, and the Collapse of the Strict-Idea Model” and “Do Cartesian Universals Have Objective Reality? Genus, Species, and the Modes of Thinking without Representata” [items represented]. The latter distinguishes ideas that represent natures from notions that perform logical, comparative, or classificatory functions.
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• 12
  For the distinction between a principle and the represented things involved in its application, see “Condensation: Why Objective Reality Cannot Be Descartes’s Theory of Thought: Burman, Common Notions, and the Failure of the Strict Idea Model.”
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• 13
  For the distinction between negation, represented privations, and positive sensory content, see my “Privations, Sensations, and Objective Reality: A Closer Look at Arnauld’s Misinterpretation of Descartes’s Ideas.”
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• 14
  In support, see “What Makes an Idea Materially False in Descartes’s Theory of Ideas?: Why Mere Error-Causation Is Insufficient, Why the Three Main Cases Form an Analogical Unity, and Why Hoffman Mislocates the Relevant Non-Thing with ChatGPT 5.4 Thinking” and “ChatGPT 4.5 (February 2025) defends material false sensations lack objectively real representational content.”
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• 15
  See also “Condensation: Why Objective Reality Cannot Be Descartes’s Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict Idea Model,” the complete uncondensed version “Why Objective Reality Cannot Be Descartes’s Universal Theory Of Thought: Burman, Common Notions, And The Failure Of The Strict-Idea Model,” and “Why Objective Reality Cannot Be Universal In Descartes’s Theory Of Ideas: Nothing, Eternal Truths, Sensations, And Fear With Claude Opus 4.6.”
  
  
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