Book Chapter One Tone

October 1, 2026

Chapter One: Against the Universal Attribution of Objective Reality and Internal Representation to Cartesian Ideas

Introduction

Must every thought Descartes calls an idea contain objectively real representational content, or at least internally represent something even if it lacks objective reality? In the Third Meditation, his strict use identifies ideas that are as if images of things (tanquam rerum imagines; AT VII 37; CSM II 25). Descartes also calls sensations and appetites ideas (Fourth Replies, AT VII 234; CSM II 163–64), and expressly includes volitions because they are immediately perceived (Third Replies, AT VII 181; CSM II 127). His broad definition includes any thought of which the mind is immediately aware (Second Replies, Definition II, AT VII 160; CSM II 113). Even the idea of nothing receives consideration in the reported conversation with Burman (AT V 153; CSMK III 338). I reject the assumption that all these ideas contain the objectively real representational content that belongs to strict ideas, or that they must internally represent something even if they lack objective reality.

I argue that some ideas in Descartes’s broad sense contain no objectively real representational content and have no internal representation.¹ A cold sensation is one of my principal examples. Its phenomenal coolness is genuinely felt, and its connection with a bodily cause allows it to function as a natural sign.² The sensation’s experienced coolness and its natural signification of a bodily cause do not establish that it contains objectively real content representing that cause. On my interpretation, the sensation has positive phenomenal content and external signification without containing any objectively real representation.

Establishing that a sensation lacks objective reality does not yet refute the claim that every Cartesian idea internally represents something, because a commentator might hold that the sensation internally represents a subject matter without objectively real content. Descartes continues to call color and cold ideas even when considering their failure to represent anything real,³ and Claudia Lorena García takes materially false sensory ideas to represent non-things despite lacking objective reality.⁴ If García holds that materially false sensations internally represent non-things without objective reality, my argument must explain why those sensations lack internal representation as well as why they lack objectively real content.

The stronger thesis holds that every Cartesian idea contains objectively real representational content. The weaker thesis holds that every idea internally represents a subject matter. García’s treatment of sensations illustrates why rejecting the first need not amount to rejecting the second.

My Restriction Thesis holds that strict ideas necessarily contain objectively real representational content, while some broad-sense ideas contain none. The representatum, or item represented, has objective being in a strict idea through that content. I also defend the connection between objective reality and internal representation against interpretations that separate them. Sensations can externally represent their causes through natural signification even when, on my account, they contain no objectively real content representing those causes.

1.1. Two Universal Claims, Not One

◇ The stronger thesis: Every Cartesian idea, including every idea in the broad sense, contains some objectively real representational content.

◇ The weaker thesis: Every Cartesian idea, including every idea in the broad sense, internally represents a subject matter.

Fearing a lion includes objectively real content representing the lion even though the fear is a non-representational affective aspect of the same thought. This is enough to satisfy the stronger thesis, which attributes some objectively real content to every idea without requiring every aspect of the idea to be representational.

A defender of the weaker thesis might hold that the idea of nothing, the common notion ex nihilo nihil fit (“From nothing, nothing comes”), or a cold sensation internally represents something despite lacking objective reality. I argue that Cartesian internal representation requires objectively real content, so any proposed representation without it must identify what the particular idea represents and explain how it represents that subject matter. Throughout the book, OR abbreviates objective reality, and an OR-bearing idea is one that possesses it.

Universal objective reality entails universal internal representation because objectively real content represents a subject matter within the idea. A complete idea lacking internal representation would refute both theses, but establishing only the absence of objective reality would still allow a defender of the weaker thesis to propose some other account of internal representation.

The argument that a cold sensation lacks objective reality occupies Chapter Four. In Chapter Five, I examine proposals that secondary-quality sensations internally represent something despite lacking objective reality and argue that these sensations have no internal representation. Their lawful connections with bodily causes nevertheless allow them to signify those causes, a relation I call external representation.

1.2. Which Ideas Are Included?

The assertion that all ideas represent can conceal a disagreement over what counts as an idea. If “idea” is reserved for thoughts of objects, sensations can be excluded from the outset. Descartes’s broad use prevents that exclusion: the question is what sensations contain once they have been admitted among his ideas.

In the Third Meditation, Descartes identifies the thoughts he calls ideas in the strict sense:

Some of my thoughts are as it were the images of things, and it is only in these cases that the term ‘idea’ is strictly appropriate—for example, when I think of a man, or a chimera, or the sky, or an angel, or God. (AT VII 37; CSM II 25)⁵

Descartes includes a chimera, a mythical creature with a lion’s head and body, a goat’s head rising from its back, and a serpent for a tail. An idea can represent this creature although no such animal exists. The examples of an angel and God also make clear that representing a thing need not involve picturing it. The strict ideas in this passage are alike in having represented subject matter, despite these differences in what they represent and how they represent it.

In the geometrical exposition appended to the Second Replies, Descartes defines “idea” more broadly:

I understand this term to mean the form of any given thought, immediate perception of which makes me aware of the thought. (AT VII 160; CSM II 113)

A cold sensation qualifies under this definition because the mind is immediately aware of its experienced coolness. I argue that the sensation contains no internal representation of a bodily quality, its cause, or itself. The opposing interpretation must explain why experiencing the coolness requires a represented subject matter.

The broad use occurs in a formal definition, not merely in an incidental remark. Descartes also defends it expressly when Hobbes objects to his use of “idea”:

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. (AT VII 181; CSM II 127)

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. (AT VII 181; CSM II 127)

Descartes counts wanting and fearing as ideas because the mind immediately perceives them, but the examples also involve wanting something and fearing something. They consequently support the broad use of “idea” without showing that the complete volitional or affective thought lacks represented content.

Steven Nadler accepts the broad use but holds that every idea falling under it contains a strict idea supplying represented content.⁶ Fearing a lion is compatible with his account because the same thought represents the lion and has fear as an affective aspect. The cold sensation is the difficult case for Nadler’s extension of this account to every broad-sense idea: unlike fearing a lion, it has no evident represented object distinct from its felt character. In Chapter Four, I examine the proposed objects of a cold sensation and argue that none supplies objectively real representational content within the sensation.

1.3. Definitions and Distinctions

I use DTOI baseline for my interpretation of Descartes’s theory of ideas. Its central distinctions concern what an idea is as a mental mode, what is experienced in it, what it internally represents, and what it signifies through its connection with a bodily cause. Material falsity introduces a further question: how can an idea supply a basis for false judgment before that judgment is made?

A feature can be attributed to an idea because of the mental occurrence itself or because of its relation to something else. The coolness of a cold sensation is experienced in that occurrence; being caused by contact with ice describes how the occurrence is related to a body. I call the experienced coolness internal to the sensation because it is a qualitative determination of the experience. Its dependence on a bodily cause does not make the coolness external, although the causal relation involves something distinct from the sensation.

The subscripted labels allow these different descriptions of one idea. A cold sensation is an idea_m as a modification of mind and an idea_s as a sensory experience. Calling it an idea_r-ext attributes natural signification to it through its lawful connection with a bodily cause. An “aspect of the idea” can therefore describe either its experienced character or one of its relations, and the word “aspect” alone does not distinguish the two.

Broad and strict ideas. An idea in the broad sense is the form of a thought of which the mind is immediately aware, including sensing, imagining, willing, fearing, affirming, and denying. (Second Replies, Definition II; AT VII 160–61; CSM II 113; Third Replies; AT VII 181; CSM II 127) I understand the strict use to concern thoughts that internally represent a determinate subject matter through objectively real content, with the representatum having objective being in the idea. Descartes’s image analogy describes this representation. (AT VII 37; CSM II 25) An intellectual idea of extension can represent extension without being a visual picture.

A cold sensation occurring now is an actual modification of mind, and its felt coolness is a real qualitative determination of that sensation. This actual existence is its formal being or formal reality (FB/FR). I use idea_m when considering an idea as this operation or mental mode, which is what it means to consider the idea materially. The term does not imply that the idea consists of physical matter.

Sensations, sensory appetites and passions, and imagination insofar as it presents imagery resembling sensory experience share the sensory character associated with the mind–body union. I mark these sensory ideas with idea_s, and purely non-sensory understanding, or intellectual ideas, with idea_i. These distinctions apply to how the thought occurs: confusion does not turn an intellectual idea into a sensation, and the vividness of a sensation does not reveal its bodily cause.

Consider Leo the lion. Seeing him need not include recognizing him as Leo, and understanding him as this particular corporeal substance is an intellectual cognition of an individual. Pure understanding is not confined to universals. In seeing and recognizing Leo, the objectively real content representing him belongs, on my interpretation, to the intellectual aspect of the cognition, while its sensory aspect supplies the experienced qualities. Descartes’s broader use of “intellect” covers both sensation and pure understanding, so calling the entire cognition an operation of the intellect leaves these aspects distinguishable.

In fearing Leo, the represented lion and the experienced fear likewise belong to one thought. Leo is the representatum, while fear is its affective determination. The awareness of fear belongs to the fearful thought itself and requires no second reflective act.

For an idea to internally represent something, its content must account for the presence of that subject matter in thought. In thinking of a lion, for example, the idea contains content through which the lion is thought of, whether or not a corresponding animal exists outside the mind. I call this internal representation, marked idea_r-int, because the explanation of what is represented requires that content within the mental mode. Identifying what caused the thought, or what happened at the same time, would not yet explain how the lion is present in it.

On my interpretation, objectively real content accounts for this internal representation, and the lion has objective being through that content. García’s proposal requires examining whether a sensation could internally represent a subject matter without objective reality. She must identify what the sensation represents and explain how its content accounts for that representation. I argue that secondary-quality sensations contain no such internal representation.

The sun need not be physically present in the mind for an idea to represent it. In thinking of the sun, the mind contains objectively real representational content through which the represented sun has objective being (OB). Objective being is its existence in the intellect insofar as it is represented, and it would have that existence in the idea even if no corresponding body existed outside thought.

Objective reality: OR or idea_or. In Definition III of the Second Replies, Descartes defines the objective reality of an idea by reference to what exists in the idea as represented:

[…] the being of the thing which is represented by an idea, in so far as this exists in the idea. (AT VII 161; CSM II 113)⁷

An idea of a lion contains objectively real content representing a finite substance. The lion has objective being in the idea, and its ontological rank as a finite substance determines the content’s degree of objective reality. On my interpretation, objective reality includes this determinate represented content as well as the degree of reality belonging to it.

The basic degrees are those of a mode, a finite substance, and an infinite substance. Ideas can also represent principal attributes and true and immutable natures, but attributes and natures introduce no further ranks alongside these three. A lion and a tree differ in kind yet have the same rank as finite substances, so their ideas have the same degree of objective reality. Descartes’s causal argument requires a cause with at least as much reality formally or eminently as the idea contains objectively.

The idea of God makes the distinction from formal reality especially clear. Thinking of God remains a finite modification of mind even though the content represents an infinite substance. Ideas of God and of a lion consequently share the formal rank of mental modes while differing in objective reality according to what they represent. (AT VII 40–42; CSM II 27–29)

With a cold sensation, the coolness itself is felt as a formally real qualitative determination of the sensory mental mode. I call this immediate experience presentation and argue that it requires neither an objectively represented copy of the coolness nor an internal representation of a resembling quality in a body.

A secondary-quality sensation can signify its bodily cause through the laws established by God connecting bodily processes with sensory experience. I call this natural signification external representation, or idea_r-ext, because what the sensation signifies is explained through its lawful relation to that cause. The sensation need not resemble the bodily property it signifies. Where the sensation guides the embodied person toward benefit or away from harm, its natural function also helps explain the response it prompts.

This relation does not establish that the bodily cause is represented within the sensation. Experienced coolness and natural signification could both be acknowledged by a commentator who also attributes internal representation to the sensation. My disagreement with that commentator requires examining the alleged represented content.

Dropsical thirst illustrates the difference between signifying a bodily condition and guiding action successfully. The appetite arises through the mechanism that ordinarily prompts drinking, but drinking would harm this patient. Its bodily cause is real even though the benefit suggested by the thirst is absent.

The intensity with which a quality is felt does not determine whether it is perceived with clarity and distinctness or with obscurity and confusion. In Principles of Philosophy I.68, Descartes allows pain and color to be clearly and distinctly perceived as sensations or thoughts despite confusion about what exists in bodies. I.45–46 gives his definitions of clarity and distinctness. (AT VIIIA 21–22, 33; CSM I 207–8, 217) The perceiver can thus recognize the felt quality as a sensation and still misunderstand its physical cause.

Underdetermination and the epistemic upgrade. Felt coolness does not tell the perceiver what cold in a body consists in. Descartes leaves unsettled “whether cold is merely the absence of heat or vice versa, or whether both of them are real qualities, or neither is.” (AT VII 44; CSM II 30) I call this failure to determine the nature of bodily cold underdetermination. An epistemic upgrade occurs when the perceiver takes the sensation to disclose that nature, as when the ice is judged to possess the very qualitative character felt in the experience. The sensation can encourage this attribution before the judgment is made.

An obscure representation may reveal little about its object and still contain objective reality.

The difficult question is whether any such represented content occurs in a bare sensation, including the minimal content proposed by interpretations that otherwise acknowledge how little sensation reveals.⁸

Material falsity: MF. On my interpretation, an idea is materially false when its own presentational or representational character presents what is not a thing as if it were a thing (cum non rem tanquam rem repraesentant; AT VII 43; CSM II 30), supplying a basis for false judgment before assent. In the cold case, genuinely felt coolness encourages the attribution of a mental quality to a body. In the false-god case, objectively real content represents a supposed finite being as genuinely divine. The misleading character belongs to the idea in each case, although only the latter, on my account, contains objective reality.

An idea can be misunderstood without being materially false, as when someone mistakes a fictional character entertained as fiction for an actual person. A hypothesis considered merely as a possibility likewise need not present its subject matter as actual. Material falsity belongs to the idea’s own presentation or representation and supplies a basis for a particular false judgment, whether or not the thinker ever assents to that judgment.

An idea can incline the thinker toward a particular false judgment before assent occurs. I call this tendency MF-inclination and use MF-degree for the scope for error the idea supplies. Descartes compares ideas on this basis in the Fourth Replies:

Yet ideas which give the judgement little or no scope for error do not seem as much entitled to be called materially false as those which give great scope for error. (AT VII 233; CSM II 163)

His comparison places confused ideas freely constructed by the mind, including idolaters’ ideas of false gods, below confused sensory ideas such as color and cold, subject to the qualification that the sensory ideas represent nothing real. Sensory appetites give the greatest scope for error, with dropsical thirst as the example. (AT VII 233–34; CSM II 163–64) I label the cases in their order of discussion: MF1 for cold and other secondary-quality sensations, MF2 for false gods, and MF3 for dropsical thirst. Their ascending order of material falsity is therefore MF2, MF1, MF3.

On my reading, the false-god idea contains objective reality but supplies less scope for error than the two sensory cases, which lack it. Degree of material falsity consequently cannot be measured by the amount of objectively real content. In dropsical thirst, the appetite’s urgency strengthens the prompting toward harmful drinking and thereby increases the scope for a mistaken judgment of benefit.

MF1: cold and other secondary-quality sensations. Contact with ice produces genuinely felt coolness in a formally real sensory idea, or idea_s. That experience can guide the person’s response to the ice and also incline the perceiver to judge that the ice possesses the qualitative character felt in the sensation. Phenomenal coolness is real as a determination of the mental mode, but it cannot exist as that mental quality in the physical body. The mistaken attribution concerns the nature of bodily cold, not the existence of either the sensation or its cause.

In the Fourth Replies, Descartes considers the supposition that cold is an absence and distinguishes the sensation mistakenly referred to bodily cold from coldness existing objectively in the intellect. (AT VII 233; CSM II 163) I take the positive sensory content to be phenomenal coolness. A defender of objective reality might hold that the sensation also represents the corporeal structure that causes it. Establishing that structure as the sensation’s cause would not establish that it is represented within the sensation.

The material falsity precedes the judgment that the ice possesses the felt quality. Its basis lies in the sensory presentation that encourages this attribution, even though feeling coolness is no error. The sensation can also signify its actual cause as a natural sign. Neither the occurrence of the experience nor its lawful signification amounts, on my interpretation, to a false internal representation of a bodily quality.

MF2: idolaters’ ideas of false gods. Descartes also recognizes material falsity in ideas of supposed deities:

But as for the confused ideas of gods which are concocted by idolaters, I see no reason why they too cannot be called materially false, in so far as they provide the idolaters with subject-matter for false judgements. (AT VII 233; CSM II 163)

An idolater’s idea of Zeus can represent a finite being with human characteristics and present that being as genuinely divine. This is objectively real representational content, but calling its object a god does not give it the rank of infinite substance. The confusion concerns the divinity attributed to the supposed being and supplies a basis for false judgments about its existence, powers, or worthiness of worship.

The material falsity of the idolater’s idea cannot be explained simply by Zeus’s nonexistence, since the same imagined figure can be entertained as fiction. In the materially false idea, the represented finite being appears as genuinely divine before the idolater assents to the corresponding judgment. The confused attribution of divinity belongs to the idea’s represented content.

MF3: dropsical thirst. Descartes’s third example concerns an appetite that prompts drinking when drinking would harm the patient:

Thus the idea of thirst which the patient with dropsy has does indeed give him subject-matter for error, since it can lead him to judge that a drink will do him good, when in fact it will do him harm. (AT VII 234; CSM II 164)

I take the thirst, considered as the appetite itself, to lack objectively real representational content. It nevertheless presents drinking as called for by a bodily need. The thirst is real, as are the water and the possible act of drinking, but the benefit suggested by the appetite is absent. Its prompting gives the patient a basis for the mistaken judgment before that judgment is made.

The Sixth Meditation traces how bodily processes that ordinarily prompt beneficial drinking produce thirst under these harmful conditions. (AT VII 84–89; CSM II 58–61) That physiological explanation accounts for the occurrence of the appetite. Its material falsity concerns the harmful action it encourages as beneficial.

What unites MF1, MF2, and MF3. In MF1, the cold sensation inclines the perceiver to attribute experienced coolness to the ice as though a mental quality could exist in a physical body. The confusion in MF2 concerns the genuine divinity attributed to a represented finite being. In MF3, thirst encourages drinking as beneficial when it would harm the patient.

Each idea supplies a basis for false judgment before assent, but the sensory cases do so through phenomenal presentation, whereas the false-god idea contains objectively real content that misrepresents the supposed being as divine.

Further cases and limits. Chapter Seven also considers pathological sensations, ideas of supposed scientific entities, and thoughts that treat an abstraction or nothing as a positive thing. These are proposed applications of the account, assessed by the particular false judgment each idea encourages. They should not be assimilated to harmless fiction or to hypotheses merely entertained as possibilities.

Sensations guide the embodied person toward benefit and away from harm, the natural function I refer to as their teleology. Descartes distinguishes this practical role from revealing the nature of physical objects in the Sixth Meditation. (AT VII 82–83; CSM II 57–58) Coolness may guide a useful response to ice even when the perceiver mistakes the felt quality for a property of the ice. Dropsical thirst is different: here the practical guidance itself fails. The first error concerns the nature attributed to a body, the second what would benefit it.

A sensation’s usefulness cannot be dismissed merely because the experience can encourage a false judgment. The cold sensation can fulfill its natural function without disclosing its cause’s physical nature, and the mechanism producing thirst can ordinarily preserve the body while failing under pathological conditions. My account therefore locates the sensory basis for error in the bodily attribution or practical benefit suggested by the experience. It does not require God to put false objectively real content into the sensation. Material falsity belongs to the idea before assent, whereas formal falsity belongs to the judgment when it is made.

1.4. What Would a Counterexample Have to Establish?

A counterexample to the stronger thesis must be a complete thought that Descartes counts as an idea and that lacks objectively real representational content. For a cold sensation to serve as such a counterexample, I must establish that its felt coolness is phenomenal content belonging to the sensory mental mode and that the sensation contains no objectively real representational content.

Suppose a person feels cold while understanding the ice as a corporeal substance. The intellectual thought may contain objectively real content representing the ice, but experiencing both thoughts together gives no reason to attribute that content to the cold sensation itself. Fearing a lion would not provide a counterexample, even though the fear itself is non-representational. The thought also contains objectively real content representing the lion, and attending only to its affective character does not establish that the complete idea lacks objective reality.

Objectless dread provides a counterexample because the affective experience occurs without the objectively real content present in fearing a lion. Descartes need not have discussed dread for it to fall within his broad definition of an idea: the person immediately experiences this mental state. In Chapter Five, I argue that its felt character constitutes the experience without any objectively real content representing danger or another subject matter. Such a state disproves the claim that every Cartesian idea contains objective reality.

Understanding a truth about a triangle may involve objectively real content representing the triangle. Even if the connection understood adds no further objective reality, the thought still contains that content. It would not provide a counterexample. In Chapter Three, I argue that the idea of nothing and the common notion ex nihilo nihil fit (“From nothing, nothing comes”) contain no objective reality, including in the concepts involved in understanding them.

These arguments challenge the claim that every idea contains objective reality. The weaker thesis requires a further argument, since a commentator might agree that an idea lacks objectively real content and still hold that it internally represents something. García takes this position on materially false sensory ideas insofar as the representation she retains is internal: she holds that they represent non-things despite lacking objective reality. To answer her interpretation, I must explain why a cold sensation lacks internal representation as well as objective reality.

What would account for the representation she attributes to the sensation? Feeling coolness does not by itself explain how the sensation represents anything, and its lawful connection with a bodily cause explains external signification. An account of internal representation must identify what is represented within the sensation and explain how the sensation represents it without objectively real content. In Chapter Five, I examine these proposals and argue that secondary-quality sensations have no internal representation.

1.5. Commentators on Objective Reality and Internal Representation

The commentators differ both over which thoughts count as ideas and over what it means for them to represent. Table 1.1 distinguishes their assertions about strict ideas, sensations as external signs, and internal representation in every conscious thought, with the quoted passages indicating the grounds for each classification.

García and Cunning illustrate two important departures from the universal attribution of objective reality. García retains representation in materially false sensory ideas, while Cunning excludes sensations from the category he calls ideas. I agree that secondary-quality sensations lack objective reality, but include them among Descartes’s broad-sense ideas and reject internal representation in them. The disagreement therefore extends beyond whether sensations possess objective reality.

Table 1.1. Claims That All Cartesian Ideas Contain Objective Reality or Internally Represent⁹

Commentator	Stronger thesis: Every Cartesian idea contains objectively real representational content	Weaker thesis: Every Cartesian idea is internally representational	Sources
Deborah J. Brown	Accepts (DJB1) “. . . . Descartes’s objective existence theory of ideas and the notion of material falsity. The former seems to entail that for an idea to be of x, x must have (objective) being, . . . .” (205) (DJB2) “Materially false ideas, like all ideas, have objective reality.” (207) Brown expressly includes materially false ideas in her attribution of objective reality (DJB1–2).	Entailed Acceptance of the stronger thesis entails internal representation in every idea.	Brown, Deborah J. 2008. “Descartes on True and False Ideas.” In A Companion to Descartes, edited by Janet Broughton and John Carriero, 196–215. Malden, MA: Blackwell.
John Carriero	Accepts (JC1) “I believe that this overtone continues with Descartes, so that for him, too, an idea is some form or structure—some “reality”—existing objectively in the mind . . . . However, I think it is the same story with sensory ideas. They, too, involve the existence of structure (presumably some corporeal configuration) in the mind. What Descartes says about sensory ideas is that the structure (the “reality”) that is found objectively in them is obscure and confused.” (20–21) (JC2) “. . . all ideas—whether purely intellectual (such as my idea of myself or of God) or imaginative (such as my idea of a chimera or my visualization of a triangle) or sensory (such as my idea of greenness)—exhibit or present reality to the mind: the reality contained in the thing that is being thought of exists objectively in the idea.” (158) (JC3) “On Descartes’s own view of sensory perception, the microphysical texture as it exists objectively (and obscurely and confusedly) in a sensory idea is not similar to—is not a replica of—the microphysical texture as it exists in the body.” (405) (JC4) “I think all sensory ideas, including cold in the imagined case, involve the confused importation of corporeal structure from the world, so even if cold is an absence or privation, it involves corporeal structure.” (409)	Accepts (JC5) “He says there [Third Meditation] that, although all ideas, including sensory ideas, “are as it were of things” (III.¶19; 7:44; 2:30), sensory ideas present what they present in a way that leaves open whether what is being presented is a reality or an absence of reality.” (163–64) JC2, quoted under the stronger thesis, expressly includes intellectual, imaginative, and sensory ideas in the attribution of represented reality.	Carriero, John. 2009. Between Two Worlds: A Reading of Descartes’s Meditations. Princeton, NJ: Princeton University Press.
Vere Chappell	Accepts (VC1) “It is that these are not distinct entities at all—not one individual thing and then a second, different one—but are rather one thing on the one hand, and an aspect or component of that same thing on the other. The idea_m and the idea_o only differ from one another, to use Descartes’ own expression, by a ‘distinction of reason.’” (179) VC1 explains how the materially considered idea and its objectively considered content belong to the same idea. VC3, quoted under the weaker thesis, adds that every materially considered idea represents objectively considered content.	Accepts For Chappell, every idea considered materially represents content considered objectively. The two are distinguishable within the same idea. (VC2) “From now on I shall abbreviate ‘idea in the material sense’ and ‘idea in the objective sense’ to ‘idea_m’ and ‘idea_o,’ respectively. Ideas_m and ideas_o, furthermore, are related, in that the latter are things represented by the former.” (178) (VC3) “Ideas_m and ideas_o, furthermore, are related in that the latter are things represented by the former. . . . Later on we shall see that the relation is necessary on the other side also, and that every idea_m represents an idea_o. Descartes’ position, indeed, is that there is, for every idea_m, exactly one idea_o that it represents, and for every idea_o, exactly one idea_m that represents it.” (178)	Chappell, Vere. 1986. “The Theory of Ideas.” In Essays on Descartes’ Meditations, edited by Amélie Oksenberg Rorty, 177–98. Berkeley: University of California Press.
David Cunning	Restricted scope Cunning denies objective reality to sensations while classifying them as mental modes outside the category he calls ideas. My disagreement with his classification is that Descartes also calls sensations ideas in the broad sense, so a sensation lacking objective reality belongs among the cases that challenge the stronger thesis. (DC1) “For Descartes, objective reality is something that is internal to an idea. [ . . . . ] However, it appears to be just a brute phenomenological fact that when we introspect and consider (for example) a sensation of coldness, there is nothing more to what we are considering than the quale itself. In particular, an examination of the mere sensation of coldness does not provide us with any information about the bodies that occasion it. [. . .] there is good philosophical reason for thinking that sensations do not have objective reality.” (27) (DC2) “A Cartesian sensation is a mode of mind but not an idea. If it is representational, it is not representational in virtue of having objective reality but in virtue of something else.” (18) (DC3) “A false idea of a sensation, on the other hand, might misrepresent that sensation as something other than a mode of mind. [. . .] Descartes thus says that a false idea of a sensation ‘does have something positive as its underlying subject, namely the actual sensation involved.’” (18) In DC3, the materially false idea takes the sensation as its subject matter. My account instead explains how the sensation itself supplies the basis for false judgment before assent.	Restricted scope Cunning reserves “idea” for thoughts of objects (DC4) and describes sensations as experienced qualities, or qualia (DC5). His claim that ideas are representational therefore applies to a category from which he has already excluded sensations. (DC4) “Another is that ideas are representational. Indeed, Descartes says that although something can be dubbed a ‘thought’ in a loose sense so long as it is a mode of mind, the term ‘idea’ is to be reserved for modes of mind that are of objects.” (23) (DC5) “Sensations are qualia that we perceive as a result of the impact of bodies on our senses.” (20)	Cunning, David. 2006. “Descartes on Sensations and Ideas of Sensations.” In An Anthology of Philosophical Studies, 17–32. Athens: ATINER.
Michael Della Rocca	Undetermined MDR1, quoted under the weaker thesis, attributes representation or a purport to represent to all ideas. Whether every such idea contains objectively real representational content requires a further explanation of that representation.	Qualified Della Rocca says that all ideas represent or purport to represent things. Assessing this statement as a defense of the weaker thesis requires determining whether he includes every broad-sense idea and whether the representation he attributes to those ideas is internal. (MDR1) “And, for Descartes, all ideas are representations; they are of things or at least they purport to be of things.” (146)	Della Rocca, Michael. 2006. “Judgment and Will.” In The Blackwell Guide to Descartes’ Meditations, edited by Stephen Gaukroger, 142–59. Malden, MA: Blackwell.
Claudia Lorena García	Rejects (CLG1) “Now, I disagree with Hoffman on this second point. I think that there are sufficient reasons—both of textual adequacy and of overall interpretive coherence—to think that Descartes is committed to the view that sensory ideas, not only can be, but also are materially false: that they represent non-things and lack objective reality.” (38; italics in original, but not bold)	Qualified García retains representation in materially false sensory ideas without objective reality (CLG1, CLG5–6). If that representation is internal, her account challenges my argument against the weaker thesis. Its subject matter is examined in Chapter Five. (CLG2) “Moreover, concerning obscure and confused ideas—some of which are false—one often cannot begin to tell what they represent.” (23; italics in original) (CLG3) “Ideas are those of our thoughts which are as it were of things; each of them appears to us to represent some thing, some res.” (24; italics in original) (CLG4) “Note that by saying that ideas can be materially false Descartes embraces the view that it is possible for an idea to misrepresent what it represents.” (29; bold and italic not in original) (CLG5) “I must emphasize that the reason why an idea is materially false, in my interpretation, is not that it fails to represent . . . .” (38) (CLG6) “taken formally, the idea will represent a non-thing, and will not represent any essence—which is not to say that the idea will not represent.” (46)	García, Claudia Lorena. 2000. “Descartes: Ideas and the Mark of the Mental.” History of Philosophy & Logical Analysis 3 (1): 21–53.
Dan Kaufman	Accepts (DK1) “ . . . Descartes holds that ideas in the material sense have ideas in the objective sense as their content.” (386) (DK2) “I have stated earlier that Descartes thinks that all ideas have objective being/existence. But Descartes is also committed to the fact that all ideas have some degree of objective reality.” (395)	Entailed Acceptance of the stronger thesis entails internal representation in every idea.	Kaufman, Dan. 2000. “Descartes on the Objective Reality of Materially False Ideas.” Pacific Philosophical Quarterly 81 (4): 385–408.
Steven Nadler	Accepts (SN1) “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.’ (Meditation III, AT VII: 42)” (92) (SN2) “This content of an idea, which allows us to discriminate one idea from another by its object, is what Descartes is referring to when he speaks of an idea’s ‘objective reality.’ It is what the idea represents (or, better, presents) to the mind. The objective reality of an idea is what makes the idea ‘like a picture or image’ and allows it to make something (e.g., the sun, in the case of the idea of the sun) immediately present to the mind. An idea’s objective reality gives the idea what philosophers have called ‘intentionality.’ It makes an idea the idea of something.” (91–92) (SN3) “For something to have objective being. . . . means that the thing exists in some mind insofar as it is being thought about by that mind. It is a mode of being in the understanding. . . . as the intentional object that the understanding grasps. In a word, something is in the mind ‘objectively’ when it is thought about, understood, or perceived.” (92)	Accepts (SN4) “At the core of every idea in the broad sense is an idea in the strict sense, giving it a specific content or referent.” (87) (SN5) “In the narrow sense – ‘idea’ as species – the word refers only to those mental items that are ‘as it were images of things [tanquam rerum imagines]’ or representational states. . . . Strictly speaking, however, ideas (in the narrow sense) are those states of consciousness that are image-like appearances. Ideas (in the narrow sense) are all those visions, thoughts, feelings and other imagines that stand before the mind’s eye in consciousness and that are the objects of the mind’s active attitudes . . . .” (88) (SN6) “For the most part, we can distinguish two senses of ‘idea’ for Descartes: a broad sense and a strict sense. In the broad meaning of ‘idea’—‘idea’ as genus—the word refers to any mental item, any state of the mind, whether it be an image, an affect, or a volitional act. Ideas in this general sense are states of consciousness, and these come in a great variety: perceptions, imaginings, thoughts, desires, feelings, willings, doubtings, and so on.” (87) (SN7) “In the narrow sense—‘idea’ as species—the word refers only to those mental items that are ‘as it were images of things [tanquam rerum imagines]’ or representational states. These include sense perceptions of physical things, pure intellectual thoughts (e.g., of mathematical figures), imaginings (e.g., of unicorns), dreams, and sensations and feelings (pain, pleasure). Both the sensory appearance of the sun as a small, yellow, warm disc and the conceptual understanding of the sun as an enormous body of gas are equally ideas in the narrow sense.” (87) (SN8) “In sum, then, we can say that ideas generally speaking are the states of consciousness of which the mind is immediately aware.” (88) (SN9) “This, in fact, is precisely how Descartes defines ‘thought’ in the Principles of Philosophy: ‘By the term “thought,” I understand everything which we are aware of as happening within us, in so far as we have awareness of it’ (Principles: I.9). An ‘idea,’ correlatively, is what is apprehended by the mind when one is conscious of the thought: ‘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)” (88) SN4 expressly attributes a strict representational idea to every broad-sense idea. SN5 and SN6–9 explain which thoughts Nadler includes in the broad and strict uses, making clear that he recognizes the distinction while holding that every broad idea has strict representational content.	Nadler, Steven. 2006. “The Doctrine of Ideas.” In The Blackwell Guide to Descartes’ Meditations, edited by Stephen Gaukroger, 86–103. Malden, MA: Blackwell.
Lawrence Nolan	Accepts (LN1) “For Descartes, every idea has two distinct kinds of being or reality—‘formal’ and ‘objective’—and, consequently, can be regarded in two ways. When we think of ideas as modes or operations of the mind, we are regarding them in terms of their formal or actual being. This is the kind of reality that ideas share with all actually existing things, whether material or spiritual. As modes, ideas also have the same degree of formal being as all other modes and as each other.” (174) (LN2) “In a move which will have important consequences for the ontology of mathematical objects, Descartes identifies this internal object of thought with the idea itself considered objectively. In the Third Meditation, he says that objective being is the mode of being ‘by which a thing exists . . . in the intellect by way of an idea’ (AT VII 41; CSM II 29). This does not yet state the identification between an idea and its internal object, but it is suggestive of it.” (175–76) (LN3) “But, as Chappell has noted, Descartes thinks the term res cogitata is ambiguous. Whereas Caterus uses it to refer to something outside the intellect, Descartes says he intended it to stand for the idea itself ‘which is never outside the intellect.’ The idea of the sun, for example, ‘is the thing which is thought of [res cogitata] in so far as it has objective being in the intellect’ (AT VII 102; CSM II 74–75).” (176) (LN4) “As we have seen, formal reality characterizes things that actually exist. Objective reality, by contrast, is the kind of reality that things in the intellect possess, as the internal objects of thought.” (176)	Accepts (LN5) “Since ideas are intrinsically representational for Descartes, every idea exhibits some internal object to the intellect whether or not the object exhibited has a counterpart outside the intellect. For example, I have ideas which represent other men, animals, and angels ‘even if there are no men besides me, no animals, and no angels in the world.’ (Third Meditation; AT VII, 43). While lacking actual or formal existence, these things at least have objective being in the mind.” (175)	Nolan, Lawrence. 1997. “The Ontological Status of Cartesian Natures.” Pacific Philosophical Quarterly 78 (2): 169–94.

1.6. The Strongest Textual Case for Universalism

The strongest defense of universalism brings several passages together. The Third Meditation identifies strict ideas as thoughts that are as if images of things (tanquam rerum imagines; AT VII 37; CSM II 25) and describes willing, fearing, affirming, and denying as involving an apprehended object. (AT VII 37; CSM II 26) The Second Replies then defines an idea through immediate awareness of a thought. (Definition II; AT VII 160; CSM II 113) Finally, the Third Meditation attributes objective being to ideas by their own nature (ex ipsarum naturâ; AT VII 42; CSM II 29). Read together, these passages can suggest that representation is common to every conscious thought and that objective reality explains how it occurs.

The most forceful statement is Descartes’s assertion that “[…] the objective mode of being belongs to ideas by their very nature […].” (AT VII 42; CSM II 29)¹⁰ The emphatic ipsarum refers to the ideas themselves. I accept that objective being belongs necessarily to the ideas Descartes is discussing, but identify them as the strict ideas whose represented contents and causes he has been comparing. On my reading, objective reality belongs to those strict ideas because of their representational nature. The further claim that every sensation, appetite, or other broad-sense idea contains such content requires extending Descartes’s statement beyond the ideas whose represented subject matter he has been comparing.

A universalist can accept the distinction between an idea’s formal reality and its objectively real content while attributing both to every idea, so that distinction alone cannot support my restriction. My reason for restricting the passage comes from the argument at AT VII 40–42, where Descartes compares ideas through the different things they represent and the degrees of reality those things possess. The question is whether he extends that comparison to thoughts for which no represented subject matter has been identified.

The earlier classification presents a further difficulty. In willing, fearing, affirming, and denying, Descartes says that “[…] there is always a particular thing which I take as the object of my thought […].” (AT VII 37; CSM II 26)¹¹

Descartes’s use of “always” supports attributing an apprehended object to each of the kinds of thought described in this passage. Fearing Leo includes that representation together with the experience of fear, but the passage does not identify a corresponding represented object within a bare cold sensation. Applying the account of fear to sensation would require showing what the sensation internally represents.

Kurt Smith’s Stanford Encyclopedia of Philosophy article distinguishes simple modes of thought from complex modes that include ideas as constituents.¹² Acknowledging a broad use of “idea” is thus compatible with finding representational constituents within complex thoughts. My account treats fearing Leo as one mental mode with representational and affective aspects, but the decisive disagreement concerns sensations alleged to have no representational content at all.

Although I read these passages as attributing objective reality necessarily to strict ideas without extending it to every broad-sense idea, that reading would leave universalism open to defense on other grounds unless the intellectual and sensory cases supplied counterexamples. Those cases provide the further reasons for rejecting the universal attribution itself.

1.7. The Positive Account and the Work of the Following Chapters

My Restriction Thesis retains objective reality as the content through which strict ideas internally represent their subject matter, with its degree determined by the representatum’s ontological rank. Sensations that lack this content still occur as consciously experienced mental modes and can naturally signify bodily causes. The positive account explains those features without making internal representation a condition of every Cartesian idea.

In Chapter Two, I follow the Third Meditation’s classification of thoughts into its comparison of represented contents and their causes, arguing that this comparison concerns strict ideas.

The idea of nothing, privative thought, and common notions then receive attention in Chapter Three. Their inclusion among Cartesian ideas creates a difficulty for universalism only if the complete cognition lacks objective reality, so I examine the concepts involved in understanding them as well as the thought taken as a whole.

Cold provides the principal sensory example in Chapter Four. A sensation might be said to represent a positive bodily quality or a privation, or its alleged content might instead be located in the corporeal motion and structure that cause it. Other interpretations appeal to a condition of the perceiver’s body, the sensation itself, a practical benefit, or some unspecified bodily quality. I examine whether any of these proposals identifies objectively real content within the sensation. Gueroult’s appeal to an infinitesimal degree raises a further issue, since obscurity about what is represented cannot by itself lower the ontological rank that determines its degree of objective reality.

Even if those proposals fail, García’s interpretation would allow sensations to represent without objective reality. Chapter Five examines what this representation could consist in, including proposed self-representation, privative content, and appeals to natural signification. I argue that secondary-quality sensations have no internal representation and explain their phenomenal character and natural signification. The chapter also develops the argument that objectless dread is a consciously experienced mental mode without objectively real content, providing a further counterexample to the stronger thesis.

The argument also needs an account of the ideas that possess objective reality, developed in Chapter Six, and an explanation of material falsity that accommodates both representational and non-representational ideas. Chapter Seven compares the cold sensation, the false-god idea, and dropsical thirst, including why the false-god idea supplies less scope for error despite containing objective reality. Fictional ideas and hypotheses help distinguish an idea’s own misleading character from errors someone might make about it. The useful effects of sensations also matter, because a cold experience can guide action successfully while encouraging a false judgment about the nature of the ice.

Milidrag’s account of intramental essences raises a different objection to my interpretation: whether objectively real content can remain instantiated in a finite mind when its subject matter is not being thought. In Chapter Eight, I argue against this unthought objective reality.

That conclusion would establish that objective reality requires an occurring thought, but it would not establish that some occurring thoughts lack objective reality. The latter claim belongs to the Restriction Thesis and depends on the intellectual and sensory cases examined earlier.

These arguments also locate my disagreements with the commentators. Carriero’s corporeal structure is a proposed content of sensations, and García’s representation without objective reality is an alternative account of what those sensations represent. Brown and Kaufman attribute objective reality to materially false ideas whose contents I distinguish in the three cases. Chappell, Nolan, and Nadler make the more general claim that every idea possesses objective or strict representational content. My interpretation must answer their explanations of the disputed ideas, rather than merely assign those ideas different names.

1.8. What Remains to Be Established

I reject the claim that every thought Descartes calls an idea must contain the objectively real representational content that belongs to strict ideas. Nadler recognizes Descartes’s broad use of “idea” but holds that every broad-sense idea contains a strict idea supplying represented content. We therefore agree that Descartes counts sensations as ideas, but disagree about what secondary-quality sensations contain. A passage in which Descartes calls cold an idea does not by itself count against Nadler’s interpretation, because he already accepts that cold sensations are ideas. I must also show that a secondary-quality sensation qualifies as an idea through its immediately experienced character while lacking the objectively real content that Nadler attributes to it.

Unlike Cunning, who excludes sensations from ideas, and García, who retains representation in materially false sensory ideas without objective reality, I count secondary-quality sensations among Descartes’s broad-sense ideas and argue that they lack both objectively real content and internal representation while externally signifying their bodily causes through lawful natural connections.

The reply reported in the Conversation with Burman distinguishes ideas taken “properly and strictly” from the broader use for common notions. (Conversation with Burman, AT V 153; CSMK III 338) That distinction supports reading statements about ideas of things as statements about strict ideas, although the application to any particular passage depends on its context. The negative idea of nothing and the common notion “From nothing, nothing comes” (ex nihilo nihil fit) also direct attention to thoughts whose intelligibility need not consist in representing a positive thing.

A cold sensation has positive phenomenal coolness as a formally real determination of the sensory mental mode. Its lawful connection with a bodily cause explains how it can signify that cause, while the experienced quality can incline the perceiver to attribute the same character to the ice. I argue that these features belong to a sensation whose content includes no objectively real representation.

Chapter Two begins with the apparent obstacle in Descartes’s texts: the Third Meditation’s strict ideas and the apprehended objects of willing, fearing, affirming, and denying (AT VII 37; CSM II 25–26) followed by the attribution of objective being to ideas by their nature. (AT VII 42; CSM II 29) The broad definition through immediate awareness in the Second Replies makes the extent of those claims decisive. (Definition II; AT VII 160; CSM II 113) I argue that their context preserves objective reality as necessary to strict representation without making representation a condition of every conscious thought.

Whether the proposed restriction can be sustained depends on the examinations of nothing, common notions, and secondary-quality sensations. In the cold case, where coolness is genuinely felt and a bodily cause is naturally signified, I argue that the sensation can encourage a mistaken attribution of its qualitative character to the body without internally representing that body or its cause.

NOTES

1
Broad and strict Cartesian uses of “idea.”
Descartes uses idea broadly for the form of any thought of which the mind is immediately aware, while the Third Meditation reserves the name, properly speaking, for thoughts that are tanquam rerum imagines, “as if images of things.” The passages below document these two uses.

I. Broad Cartesian Ideas (bold added for emphasis in the quotations below):

In the geometrical exposition attached to the Second Replies, Descartes defines an idea through immediate awareness of a thought:

“I understand this term to mean the form of any given thought, immediate perception of which makes me aware of the thought. Hence, whenever I express something in words, and understand what I am saying, this very fact makes it certain that there is within me an idea of what is signified by the words in question. Thus it is not only the images depicted in the imagination which I call ‘ideas’. Indeed, in so far as these images are in the corporeal imagination, that is, are depicted in some part of the brain, I do not call them ‘ideas’ at all; I call them ‘ideas’ only in so far as they give form to the mind itself, when it is directed towards that part of the brain.” (Second Replies, Definition II; AT VII 160–61; CSM II 113–14)

In the Third Replies, Descartes expressly includes volition and fear because they are immediately perceived:

“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 127–28)

“By an ‘idea’ I mean whatever is the form of a given perception.” (Third Replies; AT VII 188; CSM II 132)

In the correspondence with Mersenne, Descartes includes acts of will and explains that the idea by which willing is known need not be a second act:

“I claim that we have ideas not only of all that is in our intellect, but also of all that is in the will. For we cannot will anything without knowing that we will it, nor could we know this except by means of an idea; but I do not claim that the idea is different from the act itself.” (Letter to Mersenne, 28 January 1641; AT III 295; CSMK III 172)

“By the term ‘idea’ I mean in general everything which 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)

In the Fifth Replies, Descartes rejects Gassendi’s restriction of ideas to images in the imagination:

“You restrict the term ‘idea’ to images depicted in the imagination, whereas I extend it to cover any object of thought.” (Fifth Replies; AT VII 366–67; CSM II 253)

II. Strict characterization
The Third Meditation identifies the thoughts that receive the name “idea” proprie, “properly” or “strictly.” Descartes describes them as tanquam rerum imagines, which I translate as “as if images of things.” The English quotation below retains CSM’s “as it were”:

“Some of my thoughts are as it were the images of things, and it is only in these cases that the term ‘idea’ is strictly appropriate—for example, when I think of a man, or a chimera, or the sky, or an angel, or God. Other thoughts have various additional forms: thus when I will, or am afraid, or affirm, or deny, there is always a particular thing which I take as the object of my thought, but my thought includes something more than the likeness of that thing. Some thoughts in this category are called volitions or emotions, while others are called judgements.” (Third Meditation; AT VII 36–37; CSM II 25–26)

On my interpretation, strict ideas internally represent a subject matter through objectively real content. Willing, fearing, affirming, and denying can also contain such content while having volitional, affective, or judgmental aspects. Fearing a lion, for example, includes objectively real content representing the lion together with experienced fear, whose affective character is not itself a further objectively real representation. ↩︎
2
Gary Hatfield describes a reading of Descartes on which a sensation signifies its physical cause without revealing that cause’s microphysical nature: “Here, phenomenal color would serve as a sign of its cause, but would not specifically represent the microphysical properties of objects.” (“Rationalist Theories of Sense Perception and Mind–Body Relation,” in A Companion to Rationalism, edited by Alan Nelson [Malden, MA: Blackwell, 2005], 31–60, at 46.) Earlier, Hatfield explains that Cartesian accounts connect sensations with brain states through the laws of the mind–body union, while those brain states are causally connected with properties of external objects. (42) These lawful connections explain how a sensation can signify a physical cause without resembling it. Hatfield also considers an interpretation that assigns objective reality to sensory ideas. (46) I therefore cite his account of sensations as signs without treating him as endorsing my conclusion that secondary-quality sensations lack objectively real representational content.

Anna Ortín Nadal explains why the connections between bodily states and sensations are governed by laws even though God could have established different connections: “Thus, these correlations are not metaphysically necessary, but they do exhibit nomological necessity.” (“Descartes on Natural Signs and the Case of Sensory Perception,” Journal of Modern Philosophy 6 [2024]: 1–26, at 14.) Here, “nomological necessity” means necessity under the laws God establishes, so the bodily state and the sensation can be lawfully connected without resembling one another. Much of Ortín Nadal’s analysis concerns bodily states functioning as signs that produce sensations. She also identifies Descartes’s account of sensory perceptions themselves signifying benefit or harm to the mind, citing the Sixth Meditation at AT VII 83. (6, §1.2 and n. 9) Her discussion thus distinguishes bodily signs that produce sensations from sensations that signify something to the embodied perceiver. ↩︎
3
Descartes includes volition and fear among ideas because the mind immediately perceives them. (Third Replies; AT VII 181; CSM II 127) His inclusion of sensory states is explicit when he discusses “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).” (Fourth Replies; AT VII 234; CSM II 163) ↩︎
4
Claudia Lorena García, “Descartes: Ideas and the Mark of the Mental,” History of Philosophy & Logical Analysis 3, no. 1 (2000): 21–53, especially 38 and 46. García expressly combines representation with the absence of objective reality when she argues that “sensory ideas, not only can be, but also are materially false: that they represent non-things and lack objective reality.” (38) She later explains that representing a non-thing still counts as representing: “taken formally, the idea will represent a non-thing, and will not represent any essence—which is not to say that the idea will not represent.” (46) ↩︎
5
The English wording follows CSM II 25, with the dash rendered typographically as an em dash. I translate tanquam rerum imagines as “as if images of things,” while retaining “as it were” when quoting CSM. ↩︎
6
Nadler states: “At the core of every idea in the broad sense is an idea in the strict sense, giving it a specific content or referent.” Steven Nadler, “The Doctrine of Ideas,” in The Blackwell Guide to Descartes’ Meditations, edited by Stephen Gaukroger (Malden, MA: Blackwell, 2006), 87. ↩︎
7
Second Replies, Definition III. The bracketed ellipsis omits the introductory words of the sentence. The remaining wording and concluding punctuation follow CSM II 113. ↩︎
8
Chapter Four argues against assigning even minimal objectively real representational content to secondary-quality sensations, including Gueroult’s proposal that sensory ideas possess an infinitely small but positive degree of objective reality. See Martial Gueroult, Descartes selon l’ordre des raisons, vol. 1, L’Âme et Dieu (Paris: Aubier, 1953), 219–21. Two proposals require separate examination: that a sensation represents some bodily feature without revealing its precise nature, and that the sensation’s obscurity reduces its objective reality to an infinitesimal degree. The first proposal identifies alleged represented content, while the second assigns a degree of objective reality to that content.

An obscure representation of bodily motion would still represent a mode. Difficulty identifying the motion cannot by itself reduce its ontological rank to an infinitesimal degree. A minimal representation of corporeality would still need some corporeal subject matter represented within the sensation. ↩︎
9
How to read Table 1.1. The table classifies the statements quoted in each row according to the ideas they include and the kind of representation they affirm. Entailed means that the weaker thesis follows from the commentator’s acceptance of the stronger thesis, because objectively real representational content internally represents a subject matter. Undetermined means that the quoted statement leaves the commentator’s position on the specified thesis unsettled. Qualified identifies a question about the kind of representation affirmed or whether every broad-sense idea is included, while Restricted scope identifies an explicit limitation on which thoughts are counted as ideas. Page numbers refer to the work named in the same row. Notes accompanying quotations identify editorial emphasis, and ellipses indicate omitted wording. ↩︎
10
This quotation follows Cottingham’s translation and excerpts the first part of a sentence comparing the objective mode of being in ideas with the formal mode of being in their first and principal causes. In Chapter Two, I translate ex ipsarum naturâ as “by their own nature” and explain why this wording more directly refers to the nature of the ideas being discussed. Identifying those ideas as strict ideas requires following Descartes’s comparison of represented contents and his explanation of their causes. ↩︎
11
The quoted clause describes the object apprehended when Descartes wills, fears, affirms, or denies. He immediately adds that the thought includes more than the likeness of that object, which supports distinguishing the representation from the volitional, affective, or judicative character of the same thought. ↩︎
12
Kurt Smith, “Descartes’ Theory of Ideas,” Stanford Encyclopedia of Philosophy, substantive revision September 18, 2025, §1, accessed October 8, 2026. ↩︎