Endnotes + 

Literally, in a room heated by means of a stove. —⁠Tr. ↩ + 

The “Discourse on Method” was originally published along with the “Dioptrics,” the “Meteorics,” and the “Geometry.” —⁠Tr. ↩ + 

Holland; to which country he withdrew in 1629. —⁠Tr. ↩ + 

Harvey. —⁠Lat. Tr. ↩ + 

Galileo. —⁠Tr. ↩ + 

See second endnote. ↩ + 

The square brackets, here and throughout the volume, are used to mark additions to the original of the revised French translation. ↩ + 

The term “perception” (perceptio) has a much wider signification in the writings of Descartes and the Cartesians than in the literature of the schools of philosophy in our times. Perception is, at present, used to denote the immediate knowledge we obtain through sense, or even still further restricted to the apprehension of what have been called the primary qualities of matter; with the Cartesians, and the older philosophers generally, the word is employed in the same sense in which we use consciousness, to denote an act of mind by which we merely apprehend or take note of the object of thought or consciousness, considered as distinguished from any affirmation or negation (judgment) regarding it. Accordingly, in Cartesian literature perception is synonymous with cognition, when, in the narrower sense of the term, it is said to consist in the apprehension of a thing, or in the immediate consciousness of that which is known, as opposed to judgment and reasoning. It thus includes both the representative knowledge of imagination (and with the Cartesians, of sense), and the mediate or representative knowledge given in a notion or concept; for we cannot, either in imagination or conception, represent without being conscious of the representation, i.e., without perceiving or immediately apprehending it. Percipere in Cartesian literature is thus, with greater or less propriety, considered as equivalent to cognoscere, intelligere (in the narrower sense of these terms), rem menti propositam concipere, intueri; cogitatione sibi representare; rerum ideas intueri; res per ideas videre; rem per intellectus ideam intueri, cernere; rei ideam in intellectu habere. Perceptio is properly synonymous with perceptio simplex, apprehensio seu apprehensio simplex (q. prehensio objecti ab intellectu) intellectio simplex, visio simplex, cognitio, and less properly with conceptus, notio, idea rei. In logical language, the character of perception is expressed by saying that the act has for its object a thema simplex, i.e., in the language of Descartes, either substance or attribute, as opposed to the thema conjunctum seu compositum, or notionum complexio per affirmationem et negationem. i.e., enunciatio, or, in the language of Descartes, a truth.⁠—Prin. of Phil., P. I, § 48. Claubergius, Op. P. I, pp. 334, 503. (Ed. 1691.) Flenderus, Log. Cont. Claub. Ill. §§ 1.5. (4th Ed.) + 

To illustrate more particularly the nature and sphere of perception, as the term is used in the Cartesian school, it is necessary to attend to the division of the phenomena of consciousness, adopted by Descartes, and current among his followers. Descartes divides all our thoughts (cogitationes)⁠—and with him thought is the general name for each mode or phenomenon of consciousness⁠—into two grand classes, viz., the Activities and Passivities of mind (actiones et passiones sive affectus animae), the distinguishing element of these two classes being, that in the former case the mind of itself determines its own modification; in the latter it is determined to it, by some action, to wit, foreign from the will. The first class embraces all the acts of the will, or the volitions (volitiones sive operationes voluntatis), inasmuch as all such modifications of mind are considered by him as determinable, and actually determined, by the power of free choice or will, i.e., by the mind itself; and under volition (i.e., to use the language of his followers, latio quaedam anim tendens ad objectum in idea propositum) he comprehends judgment and will proper (velle et nolle), according as the object is regarded under the notions of the true and the false, or of the good and the bad. To the second class he refers all the cognitive acts of the mind, considered merely as apprehensive of their objects (perceptiones sive operationes intellectus), inasmuch as our apprehensions are not made arbitrarily, or at the pleasure of our will, but determined by their objects, and are thus, in a sense, passions or passivities. In this way all the acts, whether of sense, memory, imagination, or the pure intellect, are but different modes of perceiving; for in each we only know as we are conscious of, or apprehend, the object of the act. Further, as each mental modification has a reality for us only in so far as we actually apprehend or are conscious of it, it is plain that, in every actual mode of mind, there is involved a consciousness, or, in the Cartesian language, a perception; and thus we are said to perceive not only when in sense we apprehend by idea or representation extension or figure⁠—the qualities of somewhat lying beyond ourselves, or the representative object in imagination, but likewise when we are conscious of the forth-putting of an act of will or of being affected by joy or hope. More particularly as, according to the Cartesian doctrine, the consciousness of a modification of mind, a volition, for example, is, though in thought (ratione) separable, not really distinct from this modification itself, all modes of mind whatsoever, as participating of consciousness, are, in a sense, perceptions; for this implies nothing more than that they exist in consciousness. In this sense perception is not contrasted with, but comprehends volition, though extending further. As some modifications of mind, however, though only manifesting themselves through knowledge, are yet not apprehension simply or even knowledge, but to use his own phrase, have other forms, as volition, we may consider them in reference to these other characters; and as, on the Cartesian doctrine, these characters are negative of each other, we thus obtain classes not only in opposition, but in fundamental contrast. These distinguishing characteristics are, as we have seen, the qualities of activity and of passivity, which thus afford two grand divisions of the mental modifications, called respectively volitions and perceptions. + 

That perception was only logically discriminated from its object on the doctrine of Descartes, will be manifest from what follows:⁠— + 

“I observe (he says) that whatever is done, or recently happens, is generally called by the philosophers passion, in respect of the subject to which it happens, and action in respect of that which causes it to take place, so that, although agent and patient are often very diverse, action and passion nevertheless remain one and the same thing, having these two names by reason of the two different subjects to which it can be referred.”⁠—De Pass., P. I, art. 1. + 

“Our perceptions are of two species: some have the mind for their cause, and others the body. Those that have the mind for their cause are the perceptions of our volitions, and of all our imaginations that depend on it; for it is certain that we cannot will anything without perceiving by the same means that we will it; and, although in respect of our mind it may be an action to will a thing, we may say that it is also in it a passion to perceive that it wills; nevertheless, because this perception and volition are only in reality the same thing, the denomination is always made from the more noble, and thus we are not accustomed to call it a passion, but simply an action.”⁠—Ibid. Art. 19. Con. on the note in general. Art. 17. Prin. of Phil., P. I, § 32. Med. III pp. 97, 98. Ep., P. II, CXV, quoted below. Hamilton’s Reid. Note D, pp. 876, 877. Compare note II Idea. + 

Under the head of perception it may be necessary to remark farther that the term perception (perceptio) is not used in reference to sense without the adjunct sensus or sensuum⁠—the terms in this relation being sensus, sensatio, idea, and the verb sentire not percipere. ↩ + 

The meaning attached to the term “idea” in the writings of Descartes is by no means uniform or constant. The first grand distinction in the signification of the word arises from its application by Descartes to denote indifferently a material or a mental modification; and this in relation to sense and imagination. Considered with respect to these faculties, idea is sometimes applied to designate the impression on the brain or material organism generally, to which the idea proper or mental modification is attached, and at other times to mark the mental modification itself, regarded as the object of the faculty. As instances of the former application of the word, we may adduce the following passages:⁠—“Ideam quam formant hi spiritus.”⁠—Tract. de Homine, § 84. “Glandula ideas objectorum, quae in aliorum sensuum organa agunt, aeque facile recipere possit.”⁠—Ibid. § 85. “Ideas quas sensus externi in phantasiam mittunt.”⁠—Diopt. cap. IV § 6. To obviate the ambiguity incidental to this twofold and quite opposite use of the term, De la Forge, an eminent Cartesian, denominated the movement in the organism species, or corporeal species, reserving idea for the modification of the mind alone.⁠—Traité de Esprit de Homme, chap. X p. 99. Hamilton’s Reid, p. 834. + 

Descartes himself, indeed, in the course of the controversies to which his speculations gave rise, became aware of the necessity of distinguishing in expression the material from the mental idea; and in order to this he seems occasionally disposed to refuse the appellation idea to the material modification, while he more frequently uses the term image (imago), than idea in this relation. One of these passages I shall quote, not only in proof of this, but also as establishing the fact of the reality and distinctness of the material and mental modifications. “I do not simply (he says) call by the name idea the images that are depicted in the fantasy; on the contrary, I do not call them by this name in so far as they are in the corporeal fantasy; but I designate generally by the term idea all that is in our mind when we conceive a thing in whatever manner we may conceive it.”⁠—Lett. LXXV, Garnier, tom. IV p. 319. + 

It should be observed, however, that by idea in the sense of corporeal species, Descartes did not mean a picture, likeness, or image of the object existing in the brain, but simply a certain organic movement, or agitation of the nerves, determined by the object and communicated to the brain, the seat of the sensus communis. This purely material modification had, on the one hand, not necessarily any resemblance to the object which was the cause of it, and therefore was not representative of it; nor, on the other, should it be supposed that it in any way resembled, far less was identical with, the (mental) idea connected with it, since notwithstanding certain loose statements, there is sufficient ground to hold that, on the doctrine of Descartes, the corporeal impression was no object of perception or consciousness at all. As these are points of essential importance towards a right comprehension of the philosophy of Descartes, I may be allowed to enter somewhat into detail; and first of all, I shall refer to the passages in which he has distinctly laid down the doctrines here attributed to him. + 

“That the ideas which the external senses send into the fantasy are not images of the objects; or at least that there is no need of their being like them. + 

“It must be observed, besides, that the mind does not stand in need of images sent from objects to the brain in order to perceive (as is the generally received opinion of the philosophers); or at least that the nature of these images is to be conceived far otherwise than is commonly done. For, as philosophers consider in them nothing beyond their resemblance to the objects they represent, they are unable to show how these images can be formed by the objects, and received into the organs of the external senses, and finally transmitted by the nerves to the brain. And they had no ground to suppose there were such images, beyond observing that our thought can be efficaciously excited by a picture to conceive the object pictured; from which it appeared to them that the mind must be, in the same way, excited to apprehend the objects which affect the senses, by means of certain small images delineated in our head. Whereas we ought to consider that there are many things besides images that can excite our thoughts; as, for example, words and signs which in no way resemble the things they signify. And if, that we may depart as little as possible from the commonly received opinions, we may be allowed to concede that the objects we perceive are really depicted in the brain, we must at least remark that no image is ever absolutely like to the object it represents; for in that case there would be no distinction between the object and its image; but that a partial likeness (rudem similitudinem) is sufficient, and that frequently even the perfection of images consists in their not resembling the objects as far as they might. Thus, we see that engravings formed merely by the placing of ink here and there on paper, represent to us forests, cities, men, and even battles and tempests; and yet of the innumerable qualities of these objects which they exhibit to our thought, there is none except the figure of which they really bear the likeness. And it is to be remarked that even this likeness is very imperfect, since on a plane surface they represent to us bodies variously rising and sinking; and even that according to the rules of perspective, they frequently represent circles better by ovals than by other circles, and squares by rhombi than by other squares, and so on in other instances; so that in order to the absolute perfection of the image, and the accurate delineation of the object, the former more frequently requires to be unlike the latter.”⁠—Diopt. cap. IV § 6, C. § 7. Prin. of Phil., P. IV §§ 197, 198. + 

“Whoever has well comprised (says Descartes in contravention of the doctrine of Regius, that all our common notions owe their origin to observation and tradition), the extent and limits of our senses, and what precisely by their means can reach our faculty of thinking, must admit that no idea or objects are represented to us by them such as we form them by thought; so that there is nothing in our ideas that is not natural to the mind or to the faculty of thinking which it possesses, if we but except certain circumstances that pertain only to experience; for example, it is experience alone that leads us to judge that such and such ideas, which are now present to the mind, are related to certain objects that are out of us; not in truth that those things transmitted them into our mind by the organs of the senses such as we perceive them; but because they transmitted something which gave occasion to our mind, by the natural faculty it possesses, to form them at that time rather than at another. For, as our author himself avers in article 19, in accordance with the doctrine of my Principles, nothing can come from external objects to our mind by the medium of the senses, except certain corporeal movements; but neither these movements themselves nor the figures arising from them, are conceived by us such as they are in the organs of sense, as I have amply explained in the Dioptrics: whence it follows that even the ideas of motion and figures are naturally in us. And much more the ideas of pain, colours, sounds, and of other similar things, must be natural to us, to the end that our mind, on occasion of certain corporeal movements, with which they have no resemblance, may be able to represent them to itself.”⁠—Remarks on the Programme of Regius, Ep. P. I xcix (Ed. 1668), or tom. IV Lett. XXXVIII of Garnier’s Ed. + 

“Finally, I hold that all those (ideas) which involve no negation or affirmation, are innate in us, for the organs of the senses convey nothing to us of the same character as the idea which is formed on occasion of them, and thus the idea must have been previously in us.”⁠—Ep. P. II lv, or Garnier’s Ed. tom. IV Lett. LXIX. + 

“Whence do we know that the sky exists? Is it because we see it? But this vision does not affect the mind unless in so far as it is an idea, and an idea inhering in the mind itself, and not an image depicted on the fantasy.”⁠—App. Ax. 5, p. 233. + 

“I hold that there is no other difference between the mind and its ideas than between a piece of wax and the diverse figures of which it is capable. And since the receiving diverse figures is not properly an action in the wax, but a passion; so it seems to me to be also a passion in the mind that it receives this or that idea; and I consider that except its volitions it has no actions, but that its ideas are induced upon it, partly by objects affecting the senses, partly by the impressions that are in the brain, and partly also by the dispositions which have gone before in the mind itself, and by the movements of its will.”⁠—Ep. P. I CXV. + 

“The mind always receives these (its perceptions) from the things represented by them.”⁠—De Pass., part I, art. 17. + 

Among Cartesians, compare De la Forge, De l’Esprit de l’Homme, cap. X. Geulincx, Dictata in Prin. Phil. P. IV § 189. Malebranche, Recherche de la Vérité, Liv. II; De l’Imagination, chap. V § 1; also Liv. I. Des Sens, chap. X § 5. + 

I am aware that some maintain that Descartes held the material impression to be an object of consciousness, an opinion to which both Reid and Stewart incline (see Reid’s Essays on the Intellectual Powers; essay II, chap. VIII; Stewart’s Dissertation, Note N. p. 245; Elements, part I, chap. I, note, p. 45, ed. 1850). That such is not the doctrine of Descartes, is manifest from the passages already cited. It may be necessary, however, in order to a fuller consideration of the question, to refer to those doubtful statements which at first sight appear to give some countenance to the supposition. + 

I shall, first of all, quote and give references to what seem the strongest of the ambiguous passages. “I easily understand,” he says, “that if some body exists with which my mind is so united as to be able, as it were, to consider it when it chooses, it may thus imagine corporeal objects, so that this mode of thinking differs from pure intellection only in this respect, that the mind in conceiving, turns in some way upon itself, and considers some one of the ideas it possesses within itself; but, in imagining, it turns toward the body, and contemplates in it some object conformed to the idea which it either conceived of itself or apprehended by sense.”⁠—Med. VI, p. 128. + 

“The former, or corporeal species which must be in the brain in order to imagination, are not thoughts; but the operation of the mind imagining or turning towards these species, is a thought.”⁠—Ep. p. II liv. (De Pass. p.1., art. 35. Appendix, Def. II, p. 229). + 

These and similar passages might seem, at first sight, to countenance the supposition that Descartes admitted a knowledge of the corporeal species or organic impression. Such an interpretation is, however, rash and untenable, were there no other ground for rejecting it, save the various contradictions of the principles of the philosophy of which it is supposed to form a part, for these are so many and so manifest, that we could hardly suppose such a thinker as Descartes to have allowed them to escape his notice. Before showing that the passages in themselves do not really warrant the interpretation here referred to, I shall point out its general inconsistency, not only with the main principle, but with certain particular doctrines of Cartesianism, and these the most important and distinctive. + 

In the first place, then, had Descartes admitted a knowledge of the material impression, either in sense or imagination, and, be it observed, an immediate knowledge is the only supposable, he must have allowed an immediate consciousness of matter, for the corporeal species is a material object. But this would have been to contradict the fundamental principle of his philosophy, according to which, mind, on account of its absolute diversity from body, is supposed to be able to hold no immediate converse with matter, but only to be cognisant of it by means of its own modifications, determined hyperphysically on occasion of certain affections of the body with which it is conjoined. And thus, if the mind be immediately cognisant of the corporeal species, what occupies the prominent and distinctive place in Cartesianism⁠—viz., the host of mental ideas representative of the outward object, becomes forthwith the superfluity and excrescence of the system; for if the mind can take immediate cognisance of the corporeal species, i.e. of matter, why postulate a mental representation in order to the perception of the outward object? + 

But, in the second place, whether the material impression be an object of consciousness or not, Descartes must still be held to allow the existence of a mental modification or idea. The species, therefore, on the hypothesis that it is an object of consciousness is either really identical with the mental idea, or it is different from it. To take the former supposition, or that of the identity of the material and mental modifications, it will follow that mind and matter are no longer distinguishable, are no longer diverse substances, seeing their modifications coincide⁠—a tenet no less at variance with the entire course of the speculations of Descartes, than is the doctrine from which it flows with the numerous explicit statements, in which he declares the total diversity of the material and mental ideas, as modifications of substances in themselves distinct. But the organic impression, if not identical with, must be diverse from, the mental idea. Now as, on the hypothesis in question, the material idea is perceived, and as the mental is likewise an object of perception, there must be in each of the faculties of sense and imagination a twofold object. For such a doctrine, there is not the shadow of a ground in all the writings of Descartes. + 

But, in the third place, let it be supposed that Descartes did not allow the existence of mental ideas at all, and therefore only a single object in perception, and that the organic impression, even with this gratuitous allowance a palpable contradiction in the doctrine of the philosopher would arise. The organic impression, in order to constitute the representative idea of the object, must represent the object, not suggest it or represent it materially (materialiter), as a natural sign, for the object could not be simply suggested to the mind or thus represented, without appearing in a mental modification or idea, which is contrary to the hypothesis. But an object that is material, and at the same time representative, must, if it represent by itself, represent intentionally (intentionaliter); in other words, it must resemble the object it represents, or be the image or likeness of it. It is the property of mind alone to be capable of representing something different from itself, or even quite opposed, in a modification not at all resembling the thing represented; as, for example, an extended object in an unextended modification. But the resemblance of the material idea to the outward object, is a doctrine explicitly denied by Descartes.⁠—(Vide Remarks on Programme of Regius, quoted above, Prin. of Phil., P. IV, §§ 197, 198.) + 

But, finally, the whole hypothesis makes Descartes contradict not only his own doctrine of representation, but destroy the general conditions of any representative doctrine whatever: for, as the only ground on which a doctrine of representation can be supposed necessary, is that the mind is not immediately percipient of the outward object, if Descartes at the same time holds that the representation, itself material and an object external to the mind, because existing in the brain, is perceived, he must allow to the mind, at first hand, that power on the denial of the existence of which the assertion of the need of a representative object is founded. + 

These considerations are, I think, sufficient to show, that it is at least highly improbable, that Descartes meant in the passages quoted to allow to the mind a consciousness of the organic impression in sense and imagination. To have done so, would have been to fill his philosophy with anomalies and contradictions of the most palpable kind. + 

But let us attend shortly to the passages themselves, to discover whether they render such an interpretation of them imperative. In the passages quoted, the mind is said to turn itself towards the species, and these again are said to inform (informare) the mind. + 

With regard to the first phrase, conversion towards the species, it will be found, by a reference to the passages in which it occurs, that it is always used as descriptive of the acts of sense and imagination, when these are spoken of in contrast to the act of the pure intellect, or that faculty whose exercise is independent of all organic impression; and then the contrast indicated is in the origin or source of the ideas, or objects of these faculties, those of sense and imagination having their (remote) source in body⁠—those of intellect, their (immediate) origin in the mind itself. In this way, all that conversion towards the species indicates, is merely that the mind does not receive certain ideas directly from itself, but is in some way dependent for at least their actual presence on certain conditions of the bodily organism. And this, it is manifest, does not necessarily imply the consciousness by the mind of the organic impression. + 

Again, the corporeal species may in its turn be said to inform the mind (informare mentem), inasmuch as it is to it the mental modification or idea, viewed apart from its hyperphysical origin, is immediately attached, and on occasion of which it is revealed to consciousness; and this on the law of the union of mind and body, as parts of the same whole. In the same sense, Deity is said to inform the mind, in so constituting it as that in the course of the development of its powers, the knowledge of himself should naturally arise. + 

But, in the second place, the species may, in a literal sense, be said to inform the mind, for the word, in its strict acceptation, merely denotes the giving a particular form or shape to a thing; and in the Cartesian phraseology, the spiritual notions or mental ideas were but the different forms of the mind in which its acts were clothed, limited, and determined.⁠—Vide Appendix, Def. II, p. 229. De la Forge, De l’Esprit, chap. X, p. 131 and passim. Claub. Op. p. II, p. 606. + 

The doctrine of Descartes on this point seems to be well put by Chauvin, when, after noticing the doctrines of certain of the Peripatetics regarding species, he says:⁠—“There are, however, among more recent philosophers, not a few who retain the nomenclature of species impressa and expressa. But with them the species impressa is nothing more than a certain motion impressed either mediately or immediately, by external objects, on the parts of the body, and thence by the nerves transmitted to the brain, or a certain commotion of the fibres of the brain, proceeding from the agitation of the animal spirits flowing in the brain; which, as they have no resemblance to the objects of nature, are esteemed representamens of these things, on no other account than because the mind on occasion of them [i.e., the motions], makes the things present to itself, and contemplates the same in its own ideas therefrom arising.⁠ ⁠… + 

“But the species expressa is nothing more than that notion of the mind which is expressed on the presence of the species impressa, and by attention to and inspection (intuitione) of which the thing itself is known.”⁠—Lexicon Rationale, Species (1692). Con. Prin. of Phil., part IV §§ 189, 197, 198. + 

But, lastly, the whole ambiguity is probably due to the extreme timidity of the philosopher, and his anxious solicitude to bring the results of his own independent reflection into an apparent harmony with the opinions generally received in his time; which led him frequently to clothe his really new doctrines in the current forms of expression. + 

There is thus, not even on the special ground of the ambiguous passages themselves, any reason to suppose that Descartes ever departed from a doctrine essential to the consistency of his philosophy, viz., the non-consciousness of the organic impression. So much for idea as a material or organic modification. + 

We must now, however, consider idea in reference to mind, i.e., as an object of consciousness. In this relation the fundamental notion to be attached to the term, as used by Descartes and the Cartesians, is that of a representative thought, or an object of consciousness, in and by the knowledge of which we become aware of something distinct from this object itself. Idea, Descartes says, is to be taken “pro omni re cogitata quatenus habet tantum esse objectivum in intellectu.”⁠—Diss. de Meth. P. IV note. “Idea est ipsa res cogitata quatenus est objective in intellectu.”? Again, idea is “cogitatio tanquam rei imago.”⁠—Con. Med. III 97, and Works passim. De La Forge, De l’Esprit, chap. X pp. 128, 131. + 

It is necessary, however, with a view to an adequate understanding of the Cartesian philosophy, to distinguish the two aspects under which the same idea was viewed by Descartes and his followers. The mental idea, while really one and indivisible, was considered in two logically distinct relations, viz., both as an object and as a medium of knowledge, that is, in reference to the mind knowing and the object known. This distinction is made by Descartes in several passages of the Meditations. Thus, “If ideas are taken in so far only as they are certain modes of consciousness, I do not remark any difference or inequality among them, and all seem in the same manner to proceed from myself; but considering them as images, of which one represents one thing and another a different, it is evident that a great diversity obtains among them.”⁠—Med. III p. 100. Preface of Med. p. 72. + 

This distinction of idea as act and as representative object, pervades the whole body of Cartesian literature. Thus, to take an example, “Every concept or idea,” says Clauberg, “has a twofold dependence: the one from the conceiving and thinking intellect, in as far as it is an act; the other from the thing conceived or like, of which, to wit, it is the representation or image, or whence it is struck out by imitation.”⁠—Op. P. II p. 607 (Ed. 1691). Con. De la Forge, De l’Esprit, chap. X pp. 128, 131. Flenderus, Logica Contracta Claubergiana (4th ed.) § 5, p. 12. + 

Idea has thus with the Cartesians a twofold relation or dependence (realitas, perfectio, esse, dependentia). In so far as it is an act or mode of the mind (operatio mentis, intellectus), idea possesses a formal and proper being (esse formale seu proprium); in so far as it is the representation of the object thought (imago rei cognitatae), or in the place of that object (in vice illus), it has an objective or vicarious being (esse objectivum sive vicarium). Again, idea, as standing in this double relation or dependence, is said to have a twofold cause, viz., an efficient and an exemplary. In so far as a mode of consciousness, the idea has its efficient cause in intellect or in the mind itself (uti operans suae operationis causa); in so far as representative, the object is the exemplary cause, standing in relation to the idea as the archetype to the ectype, the principal to the vicarious. + 

It is the discrimination of idea as a mental operation or representative object, which affords the logical distinction of perception and idea, to be met with on all hands in Cartesian literature. “By the term ‘idea,’ ” says Descartes himself, “I understand that form of any thought by the immediate perception of which I am conscious of that same thought.”⁠—Appendix, Def. II p. 229. + 

“I have said,” says Arnauld, “that I take perception and idea for the same thing. It should be observed, however, that this thing, although one, has two relations: the one to the mind which it modifies, the other to the thing perceived, in so far as it is objectively in the mind, and that the word ‘perception’ more distinctly marks the former relation, and idea the latter. Thus, the perception of a square marks more directly my mind as perceiving a square; and the idea of a square marks more directly the square in so far as it is objectively in my mind.”⁠—Des Vraies et des Fausses Idées, chap. V Def. 6. Con. De la Forge, De l’Esprit, chap. X pp. 128, 140. + 

It should be observed, however, with regard to this distinction of idea and perception, that with Descartes perception is sometimes used where, in accordance with the propriety of language, we should have expected idea. Thus he says, “The mind always receives these (its perceptions) from the things represented by them.” (De Pass., P. I art. 17.) On the other hand, we find idea where, in accordance with his general nomenclature, we should have looked for perception. “When I will and fear, because at the same time I perceive that I will and fear, the volition itself and fear are reckoned by me among ideas.”⁠—Ob. et Resp. Tertiae, Ob. V p. 98 (Ed. 1670). + 

Looking to ideas as the immediate objects of knowledge or perception, and considering them in relation to the faculties of which they are the objects, they may be classed as ideas of sense, of imagination, and of the pure intellect, in the exercise of each of which powers we are said to be apprehensive or percipient of ideas. But, as the objects of these powers, ideas differ both in their origin, and according to the character of the objects they represent. In the first relation, ideas arise either simply from the mind, as those of the pure intellect, or from the mind on occasion of body, modified by the corporeal species, as those of sense and imagination. Considered as to their origin, the ideas of sense and imagination thus stand in contrast to those of the pure intellect, for in sense and imagination there is always a physical impression or corporeal species as the cause or occasion of the mental idea; whereas the intellect, as deriving its ideas from the mind itself, has no need of a material organ or of corporeal species. The ideas of sense and imagination, while they agree in being the result, though hyperphysically determined, of a physical antecedent in the form of the corporeal species, and thus in both depending on the bodily organism, nevertheless differ in this, that the species to which the idea is attached is in the case of sense immediately dependent on the presence and action of external objects; while in imagination it depends only remotely on external objects, and proximately on the will, the memory, and the action of the animal spirits. + 

But the chief contrast of ideas arises from the character of the objects they represent. In this relation, on the Cartesian doctrine, ideas fall into two great classes. The first comprehends all ideas of the individual and picturable, in other words, all the objects of sense and imagination; the second contains all our notions of the general, relative, or unpicturable⁠—in other words, the ideas of the pure intellect. (Con. Med. VI pp. 127⁠–⁠129; Prin. of Phil. P. I § 73. Lett. LXXV, vol. IV. p. 318 of Garnier’s ed., or vol. VI, L. LXII duod. ed. De la Forge, De l’Esprit, chap. XVIII pp. 298⁠–⁠302.)⁠—Under sense it should be observed that idea, in the writings of Descartes as well as of others in the Cartesian school, denotes indifferently the apprehension of the primary and the sensations of the secondary qualities of matter. Thus, Descartes speaks of the sensation or idea (sensus vel idea) of colour and heat. Malebranche limited idea (idée) to the apprehension of the primary, reserving sentiment to designate the sensations of the secondary qualities.⁠—As the secondary qualities on their subjective side were held by the Cartesians to be merely modifications of the percipient subject, and not to exist in nature as in consciousness, idea as applied to them (which was not generally the case out of the writings of Descartes), was not representative. Vide Prin. of Phil. P. I §§ 69, 70, 71. ↩ + 

After what has been already said of the twofold relation of idea in the philosophy of Descartes, it is unnecessary to add much by way of explanation of the term “objective reality.” This, as we have said, denotes that aspect of a representative thought in which it is considered in relation to the object represented; hence the object is said to possess objective reality in so far as it exists by representation in thought (quatenus objicitur intellectui). This use of the term objective, it will be remarked, is precisely opposed to the more modern (Kantian) acceptation of the same word, and corresponds, to a certain extent, with the counter-term subjective; for objective reality (i.e., the reality of representation) is in truth a subjective reality. + 

It may be of importance to note the two relations from which the representative reality of an idea is distinguished in Cartesian literature, with their appropriate designations. In the first place, the representative perfection (being) of an idea, was distinguished from the object of the idea in so far as it possessed an absolute existence, or existence independent of thought. In this relation the object was said to possess realitas actualis, formalis, as opposed to realitas objectiva. (Con. Med. ili. pp. 100, 101; Med. VI p. 133.) The object as it exists in nature was by other philosophers, and among these by some of the Cartesians, called ens principale, reale, fundamentale (quasi fundamentum ideae). + 

In the second place, the representative being of an idea was distinguished from its relation to the mind of which it is the act, and in this aspect idea, so far as act, was said to possess esse reale, materiale, formale (q. forma quaedam mentis, and this in contrast with objectivum), proprium; in relation to the object represented, it was said to possess esse intentionale, formale (and this in contrast with materiale), objectivum, vicarium; these are the strictly contrasted appellations. The esse objectivum was also called representativum, cognitum, in mente, tanquam in imagine, per imitationem. Con. Claub. Op. P. II pp. 607⁠–⁠617. Hamilton’s Reid, pp. 806, 807. ↩ + 

“From the senses, that is, from sight, by which I first perceived light, and then by its aid colours, figures, magnitudes, and all similar things; through the senses, that is, through hearing, in apprehending the words of men.”⁠—Claubergius, in h. loc. Op. P. II p. 1182. ↩ + 

Thought (cogitatio, pensée), in the Cartesian phraseology, applied to designate all that takes place within us, of which we are immediately conscious, i.e., all the modifications of the mind or thinking principle. Thought is thus but another term for consciousness, and embraces all the acts of the will, the intellect, the imagination, and senses.⁠—Med. III p. 97; Prin. of Phil. P. I § 9; Resp. ad. Sec. Object. Def. I (Appendix, p. 229). + 

“Thought,” says De la Forge, “I take for that perception, consciousness, or internal knowledge which each of us feels immediately by himself when he perceives what he does or what passes in him.”⁠—De l’Esprit, chap. III p. 14, chap. VI p. 54. Arnauld, Des Vraies et des Fausses Idées, chap. V, Def I. + 

“Mens,” says Claubergius, “si vult cogitat, si non vult cogitat, si amat cogitat, si odit cogitat, si affirmat cogitat, si negat cogitat, si dubitat cogitat, si demonstrat cogitat, somniando cogitat, vigilando cogitat, sentiendo cogitat, imaginando cogitat, etc., atque ita in qualibet ejus functione cogitatio involvitur.” Op. Prin. p. 600; P. I p. 188; Log. P. I § 102. + 

Consciousness is thus, in the doctrine of the Cartesians, the general condition of our mental modifications, and in no way really distinct from the activities and passivities of which it is the condition. Though, in a sense already explained (as opposed to volition), perception is said to be contained under consciousness as its genus, they are yet nearly convertible terms. The difference between the two forms of expression seems to be, that thought, while embracing all the modifications of mind, whether volitions or perceptions, is not distinguished from the former as a passivity, while perception is. Thought, as thus denoting a mental modification both in its active and passive relation, marks the opposition and contrast of the modification to its negative, the extended, i.e., matter, while viewed as a perception the phenomenon is regarded mainly in reference to its simple existence in consciousness, or as an apprehended property of mind. It seems to be in accordance with this view that the mind is uniformly spoken of as res cogitans (not percipiens) when opposed to its negative, the unthinking and extended. ↩ + 

By innate idea, Descartes meant merely a mental modification which, existing in the mind antecedently to all experience, possesses, however, only a potential existence, until, on occasion of experience, it is called forth into actual consciousness. + 

It is worthy of remark, in connection with the question of innate ideas, that the chief ground on which Descartes holds that certain of our judgments are prior to experience and native to the mind, is the impossibility of deriving them as universal from individual corporeal movements, which, if efficient, could give rise to modifications merely individual. + 

It will be seen, however, from the passages quoted below, and from a comparison of them with the passage quoted at pp. 198, 199, of these notes, that Descartes held a much wider doctrine of innate ideas than the modern, and one the principle of which could not fail sooner or later to result in the doctrine of Occasional Causes, to explain the connection between the corporeal antecedent, which had no causal power, and the rise of the mental modification into actual consciousness. + 

The following is the article (XII) in the Programme of Regius which gave occasion to Descartes to make an explicit statement of his doctrine of innate ideas. + 

“Mens,” says Regius, “non indiget ideis, vel notionibus, vel axiomatibus innatis: sed sola ejus facultas cogitandi, ipsi, ad actiones suas peragendas, sufficit.” On this Descartes remarks: “In this article he (Regius) appears to differ from me merely in words; for when he says that the mind has no need of ideas, or notions, or axioms that are innate [or naturally impressed upon it], and meanwhile concedes to it a faculty of thinking (that is, a faculty natural to it or innate), he affirms my doctrine in effect, though denying it in word. For I have never either said or thought that the mind has need of innate (natural) ideas, which are anything different from its faculty of thinking; but when I remarked that there were in me certain thoughts which did not proceed from external objects, nor from the determination of my will, but from the faculty of thinking alone which is in me, that I might distinguish the notions or ideas, which are the forms of these thoughts, from others adventitious or factitious, I called them innate in the same sense In which we say that generosity is innate in certain families, in others certain diseases, as gout or gravel, not that, therefore, the infants of those families labour under those diseases in the womb of the mother, but because they are born with a certain disposition or faculty of contracting them.” + 

Again, on art. XIII, he says⁠—“What supposition is more absurd than that all the common notions which are in the mind arise from these corporeal motions, and cannot exist without them? I should wish our author to show me what that corporeal movement is which can form any common notion in our mind; for example⁠—that the things which are the same with a third are the same with each other, or the like. For all those motions are particular; but these notions are universal, and possess no affinity with motions, nor any relation to them.” + 

“He (Regius) proceeds, in article XIV, to affirm that the very idea of God which is in us arises not from our faculty of thinking, in which it is innate, but from divine revelation, or tradition, or the observation of things. We shall easily discover the error of this assertion, if we consider that a thing can be said to be from another, either because that other is its proximate and primary cause, or because it is simply the remote and accidental, which, in truth, gives occasion to the primary to produce its own effect at one time rather than at another. Thus, all workmen are the primary and proximate causes of their own works; but they who commission them, or offer payment for the execution of the works, are the accidental and remote causes, because the works would not perhaps have been done without the order. It cannot be doubted but that tradition or the observation of things is the remote cause, inviting us to attend to the idea of God which we possess, and to exhibit it in presence to our thought. But that it is the proximate cause (effectrix) of that idea can be alleged only by one who holds that we can know nothing of God beyond the word God, or the corporeal figure exhibited to us by painters in their representations of God. Inasmuch as observation, if it be of sight, presents nothing of its own proper power to the mind except pictures, and pictures whose whole variety is determined solely by that of certain corporeal movements, as our author himself teaches; if it be of hearing, observation presents nothing but words and sounds; if of the other senses, it presents nothing that can be related to God. And, indeed, it is manifest to every one that sight properly and by itself presents nothing except pictures, and hearing nothing but words or sounds; so that all which we think beyond these words or pictures, as the significates of them, are represented to us by ideas coming from no other source than our faculty of thinking, and therefore natural to it; that is, always existing in us in power. For to be in any faculty is not to be in act but in power only, because the very word faculty designates nothing but power.”⁠—Lett. XXXVIII, Garnier’s ed. tom. IV. Not. in Prog. Latin (1670), p. 175. + 

“On the celebrated question (says De la Forge) as to whether the ideas of the mind are born with it, or acquired, I reply that they are both one and other. They are born with it, not only because it has never received them from the senses, but also because it is created with the faculty of thinking and forming them, which is the proximate and principal cause of them; in the same way that we say gout or gravel is natural to certain families, when the members of them bring with them proximate dispositions to those maladies. But those ideas are acquired, and not natural, if by natural we understand that they are in the substance of the soul as in a conservatory, in the manner in which pictures are disposed in a gallery, that we may consider them as we please; for there is none of them in particular that needs to be actually present to our mind, which, being a thinking substance, can have nothing actually present to it of which it has no knowledge. It is for this reason they are contained in the mind only in power, and not in act.”⁠—De l’Esprit, chap. X, pp. 143, 144. Con. Clauberg. on Med. III, Op., P. I, 391. ↩ + 

Besides the application of the word formal already noticed, viz. (1), in opposition to objective, to denote the object as it exists in nature; and (2) as a synonym for objective in contrast to material, to denote the idea so far as it is a representation, there is still another use of the term in the writings of Descartes and in the Cartesian literature. In this third application, formal is opposed to eminent, and refers to the relation of cause and effect. The contrast indicated by these terms in this relation is in regard to the manner in which a cause is said to contain its effect. A cause, as the sum of the perfection or reality of its effect, may contain this reality in either of two ways, and must in one of them. On the one hand, if the perfection of the effect be contained in the cause in the same mode in which it exists in the effect, or, if the cause be only possessed, in this respect, of equal perfection with the effect, the reality of the effect is said to be in the cause formally (formaliter, q. d. secundum eandem formam et rationem). Thus, the print of the foot has formally the quantity and figure of the foot, and is thus formally in its cause. In the same way, any absolute perfection is formally in God. On the other hand, if the effect be contained in the cause, not as it is in itself, or according to its intrinsic form, essence, or proper definition, but in a higher grade or mode of perfection (gradu, modo eminentiori), it is said to be in its cause eminently. In this sense the Divine intellect contains the human, since God knows, but without the imperfections incident to the exercise of our faculties of cognition, A cause containing eminently thus contains all the reality of the effect more perfectly than the effect itself. This distinction, borrowed from the schoolmen, has an important application, in the philosophy of Descartes, to the question of the proof of the existence of God through his idea.⁠—Con. Med. III, p. 41, etc. Appendix, Def. IV, p. 230; Ax. IV, p. 233. Spinoza, Prin. Phil. Cart., P. I, vol. I, p. 16 (Paulus.). Clauberg. Exercit. VI, p. 613, §§ 5, 6 (Ed. 1691). Flender. Log., § 50. Chauvin, Lex. Rat., voc. Continere. De Vries (Anti-Cart.) Exercit. VI, § 4, pp. 55, 56 (Ed. 1695). ↩ + 

Regius; see La Vie de M. Descartes, reduite en abrege (Baillet). Liv. VII, chap. VII —⁠Tr. ↩ + 

Instead of “local motion,” the French has “existence in any place.” ↩ + 

In the French, “which alone has the power of perceiving, or of being conscious in any other way whatever.” ↩ + 

“As what they represent of their object has more perfection.” —⁠French ↩ + 

After limits, “what of them we do conceive is much less confused. There is, besides, no speculation more calculated to aid in perfecting our understanding, and which is more important than this, inasmuch as the consideration of an object that has no limits to its perfections fills us with satisfaction and assurance.” —⁠French ↩ + 

In the French, “since extension constitutes the nature of body.” ↩ + 

In the French, “because our perceptions arise from impressions made upon us from another source,” i.e., than ourselves. ↩ + 

“To Essay to Comprehend the Infinite.” —⁠French ↩ + 

“We will not stop to consider the ends which God proposed to himself in the creation of the world, and we will entirely reject from our philosophy the search of final causes!” —⁠French ↩ + 

“Faculty of reasoning.” —⁠French ↩ + 

The last clause, beginning “bearing in mind,” is omitted in the French. ↩ + 

Intelligence, understanding (intellectus), is the general name in Cartesian literature of the powers of cognition in contrast to those of will; and in this sense the term comprehends all the acts, whether of sense, memory, imagination, or of intellect proper. But intelligence has, besides its general, a special and restricted signification; and this especially when the qualifying epithet pure is joined with it. Pure intellection (intellectio pura) denotes not knowledge in general, but the knowledge, whether individual or general, of the mental phenomena, and generally of all those objects we are capable of thinking in the narrower sense of the word, but cannot imagine, or hold up to our mind in an image or picture. In a word, with the Cartesians the pure understanding is the faculty of the unpicturable, imagination of the picturable. Whatever knowledge, therefore, we may be able to reach of mind or of God, of body in its general relations, or in such of its properties as are either too great or too minute for apprehension by sense⁠—of those judgments which are native to the mind⁠—falls within the province of the pure intellect. + 

It should be observed that in this faculty, according to its application, there is knowledge either without or with ideas⁠—in other words, either an immediate or a mediate knowledge. It is by the pure intellect alone that we take cognisance of our own mind in its phenomena, and these we can immediately, or without idea, apprehend. But of everything distinct from ourselves which we know by the intellect, we can have but a mediate knowledge, or a knowledge by idea. The distinction of the ideas of the imagination and the intellect is nearly similar to the distinction of thoughts into those of the individual and general, or of intuitions (in the older sense of the term), and notions or concepts.⁠—Con. Note II, Idea. Med; IV, p. 112. Med. VI, pp. 127⁠–⁠129. Prin. of, Phil., § 73. Lett. LXXV, Garnier, tom. IV, p. 318 (or LXII of vol. VI Ed. 12mo.), Ep. P. I, XXX. Reg. ad Direct. Ing., R. XII. De la Forge, De l’Esprit, chap. XVIII, pp. 298⁠–⁠302. Hamilton’s Reid, p. 291, note. ↩ + 

“What appears manifestly to him who considers it as he ought.” —⁠French ↩ + 

“First.” —⁠French ↩ + 

Things and the affections of things are (in the French) equivalent to “what has some (i.e., a real) existence,” as opposed to the class of “eternal truths,” which have merely an ideal existence. ↩ + 

“And generally all the attributes that lead us to entertain different thoughts of the same thing, such as, for example, the extension of body and its property of divisibility, do not differ from the body which is to us the object of them, or from each other, unless as we sometimes confusedly think the one without thinking the other.” —⁠French ↩ + 

“By the colour we perceive on occasion of it.” —⁠French ↩ + 

“Which vary according to the diversities of the movements that pass from all parts of our body to the part of the brain to which it (the mind) is closely joined and united.” —⁠French ↩ + 

“Which it perceived on occasion of them” (i.e., of external objects). —⁠French ↩ + 

“Reasonings.” —⁠French ↩ + 

The following section of the Principles is added to those given in the text, from its bearing logically and historically on the doctrine of Occasional Causes as arising out of Cartesianism:⁠— + 

“That God is the primary cause of motion: and that he always preserves the same quantity of motion in the universe. + 

“After having thus adverted to the nature of motion, it is necessary to consider its cause, and that the twofold: firstly, the universal and primary, which is the general cause of all the motions in the world; and secondly, the particular, by which it happens that each of the parts of matter acquires the motion which it had not before. And with respect to the general cause, it seems manifest to me that it is none other than God himself, who, in the beginning, created matter along with motion and rest, and now by his ordinary concourse alone preserves in the whole the same amount of motion and rest that he then placed in it. For although motion is nothing in the matter moved but its mode, it has yet a certain and determinate quantity, which we easily understand may remain always the same in the whole universe, although it changes in each of the parts of it. So that, in truth, we may hold, when a part of matter is moved with double the quickness of another, and that other is twice the size of the former, that there is just precisely as much motion, but no more, in the less body as in the greater; and that in proportion as the motion of any one part is reduced, so is that of some other and equal portion accelerated. We also know that there is perfection in God, not only because he is in himself immutable, but because he operates in the most constant and immutable manner possible: so that with the exception of those mutations which manifest experience, or divine revelation renders certain, and which we perceive or believe are brought about without any change in the Creator, we ought to suppose no other in his works, lest there should thence arise ground for concluding inconstancy in God himself. Whence it follows as most consonant to reason, that merely because God diversely moved the parts of matter when he first created them, and now preserves all that matter, manifestly in the same mode and on the same principle on which he first created it, he also always preserves the same quantity of motion in the matter itself.” —⁠Part II § 36 ↩ + 

“Common sense.” —⁠French ↩ + 

In the French this section begins, “Taste, after touch the grossest of the senses,” etc. ↩ + 

“Thus we may reckon upon having already discovered two diverse forms in matter, which may be taken for the forms of the first two elements of the visible world. The first is that of the scraping (raclure) which must have been separated from the other parts of matter, when they were rounded, and is moved with so much velocity that the force alone of its agitation is sufficient to cause it, in its contact with other bodies, to be broken and divided by them into an infinity of small particles that are of such a figure as always exactly to fill all the holes and small interstices which they find around these bodies. The other is, that of all the rest of the matter whose particles are spherical and very small in comparison of the bodies we see on the earth, but nevertheless possess some determinate quantity, so that they can be divided into others much smaller: and we will still find in addition a third form in some parts of matter, to wit, in those which, on account of their size and figure, can not be so easily moved as the preceding; and I will endeavour to show that all the bodies of the visible world are composed of these three forms, which are found in matter, as of three diverse elements, to wit, that the sun and the fixed stars have the form of the first of these elements, the heavens that of the second, and the earth with the planets and comets that of the third. For since the sun and the fixed stars emit light, since the heavens transmit it, and since the earth, the planets, and comets reflect it, it appears to me I have ground for these three differences [luminousness, transparency, and opacity or obscurity, which are the chief we can relate to the sense of sight], in order to distinguish the three elements of the visible world.”⁠—Prin. of Phil. part III, § 52. Con. Chauvin, Lex. Rat., Art. Elementum. ↩ + 

In the French this section begins, “Finally, sight is the most subtle of all the senses,” etc. ↩ + 

“The diverse figures, situations, magnitudes, and motions of their parts.” —⁠French ↩ + 

“That of Aristotle or the Others.” —⁠French ↩ + 

“Have for their end only to apply certain sensible bodies to each other in such a way that, in the course of natural causes, certain sensible effects may be produced; and we will be able to accomplish this quite as well by considering the series of certain causes thus imagined, although false, as if they were the true, since this series is supposed similar as far as regards sensible effects.” —⁠French ↩ + 

Ἐπεὶ δὲ περὶ τῶν ἀφανῶν τῇ αἰσθήσει νομίζομεν ἱκανῶς ἀποδεδεῖχθαι κατὰ τὸν λόγον, ἐὰν εἰς τὸ δυνατὸν ἀναγάγωμεν, ἔκ τε τῶν νῦν φαινομένων ὑπολάβοι τις ἂν ὧδε περὶ τούτων μάλιστα συμβαίνειν. Μετεωρ. α. 7. —⁠Tr. ↩ + 