CHAPTER LIX—That the Potential Intellect of Man is not a Spirit subsisting apart from Matter³³¹³³¹   These chapters, LIX–LXXVIII, are the most abtruse in the whole work. They are founded on the scholastic theory of the origin of ideas, which again is based on Aristotle, De anima, III, Chapp. IV, V. The theory first presupposes the doctrine of matter and form, of which there is a fair]y good account in Grote’s Aristotle, vol. II, pp. 181-196. Grote goes on to expose the Aristotelian doctrine of Nous (intellectus), as he understands it. In this exposition two points are noteworthy. (1) No account is taken of St Thomas’s distinction between potential (possibilis) and ‘passive’ (passivus) intellect. (2) A view is ascribed to Aristotle, closely allied to the views which Averroes and Avicenna ascribe to him, views which St Thomas laboriously combats as being neither Aristotelian nor correct. If these Mohammedan commentators, with Grote and many moderns, are right, Aristotle cannot be claimed as a believer in personal immortality. Still the fact that Plato steadily held the individual soul to be immortal, joined to the fact that Aristotle, who was forward enough in contradicting his master, nowhere explicitly contradicts him on this head, — as also the obscurity of the language of the De anima, — “may give us pause.”
   For any understanding of what follows it is necessary to distinguish the ‘passive intellect’ (intellectus passivus, νοῦς παθητικός), the ‘potential intellect’ (intellectus possibilis, νοῦς δυνατός, or ὁ δυνάμει νοῦς), and the ‘active intellect’ (intellectus agens, νοῦς ποιητικός).
   1. ‘Passive intellect’ is not intellect at all. It is found in the higher dumb animals; and is only called ‘intellect’ by a sort of brevet rank, because being the highest power of the sensitive soul, it comes closest to intellect and ministers to it most nearly. St Thomas calls it in dumb animals vis aestimativa; in man, vis cognativa and ratio particularis. It has no English name, but may be defined: ‘an instinct whereby the sentient soul directly recognises a sensible object as a particular something here and now present.’ See Father Bödder’s Psychologia, pp. 71-79, who apposite]y cites Cardinal Newman’s Grammar of Assent, pp. 107 sq. See too Silvester Maurus, Commentary on Aristotle, De anima, lib. III, cap. iv (ed. Lethielleux, Paris, 1886, tom. IV, pp. 94, 95). Aristotle tells us of this faculty that it perishes with the body, but that its operation is an indispensable preliminary to all human understanding, ὁ δὲ παθητικὸς νοῦς φθαρτός, κα͍ὶ ἄνευ τούτου οὐθὲν νοεῖ (De anima III, v, ult.)
   2. Much more important is the ‘potential intellect,’ — intellectus possibilis, a term occurring again and again in all the writings of the schoolmen, being founded on one word of Aristotle, De anima III, iv, 3, μηδ᾽ αὐτοῦ εἶναι φύσιν οὐδεμίαν ἀλλ᾽ ἢ ταύτην ὅτι δυνατόν (nor has it any other natural property than this, that it is able, capable, potential). It is defined by Maurus (l.c.): “the intellect inasmuch as it is capable of being [representatively] made all things, by receiving intelligible impressions of all things.” An ‘intelligible impression’ differs from a ‘sensible impression’ as the universal from the particular, e.g. as the triangle in the mind, which stands for any triangle, from the image of this particular triangle chalked on the board and taken up by sense and phantasy.
   3. Of equal scholastic importance is the ‘active intellect,’ intellectus agens, defined by Maurus: “The intellect inasmuch as it is capable of [representatively] making all things, by impressing on the potential intellect intelligible impressions of all things.” The term νοῦς ποιητκός though not actually found, is implied in De anima, III, v. The ‘active’ and ‘potential’ intellect together make up the understanding. The exact extent of the distinction between them is matter of some dispute (Bödder, Psychologia, pp. 159-163).
   What ordinary mortals call ‘intellect’ or ‘understanding,’ is the ‘potential intellect.’ It is called ‘potential’ because it is open to all intellectual impressions, and, prior to experience, is void of all impression, and has no predisposition of itself to one impression rather than to another. This by the way seems to militate against the Kantian doctrine of intellectual ‘categories,’ or ‘forms of mind.’ But it does not militate against the doctrine of heredity. Heredity works in the body, in the domain of the sentient soul: we are here concerned with pure intellect. Of that, Aristotle says it is “impassible [i.e., not directly acted on by matter], yet apt to receive the intelligible impression, or form; but has no formed impression upon it, before the process of understanding is set up.” The ‘active intellect’ on the other hand is the act of spontaneous energy, whereby the intellect transforms the image, sent up to it by sense and phantasy, from particular to universal, making out of it an ‘intelligible impression.’ A further distinction is drawn between the ‘intelligible impression’ (species intelligibilis impressa) thus created and received in the mind, and the ‘intelligible expression’ (species intelligibilis expressa), or precise act whereby the mind understands. See Bödder, Psychologia, pp. 153-156. This distinction has been already drawn by St Thomas (B. I, Chap. LIII).
   For further elucidation see Father Maher’s Psychology, pp. 304-313, ed. 4, who however speaks of intellectus patiens vel possibilis, and takes no account of the intellectus passivus of St Thomas (B. II, Chap. LX), probably because it simply is not intellect.

THERE were others who used another invention in maintaining the point, that a subsistent intelligence cannot be united with a body as its form. They say that the intellect which Aristotle calls ‘potential,’ is a spiritual being, subsisting apart by itself, and not united with us as a form. And this they endeavour to prove from the words of Aristotle, who says, speaking of this intellect, that it is “separate, unmixed with body, simple and impassible,” terms which could not be applied to it, they say, if it were the form of a body.³³²³³²εἰ ὁ νοῦς ἀπλοῦν ἐστὶ καὶ ἀπαθὲς καὶ μηθενὶ μηθὲν ἔχει κοινόν (if the intellect is a simple being and impassible and has nothing in common with anything) De anima, III, iv, 10. Also from the argument by which Aristotle proves that 123because the potential intellect receives all impressions of sensible things, and is in potentiality to them all, it must be devoid of all to begin with, as the pupil of the eye, which receives all impressions of colours, is devoid of all colour; because if it had of itself any colour, that colour would prevent other colours from being seen; nay, nothing would be seen except under that colour; and the like would be the case of the potential intellect, if it had of itself any form or nature of sensible things, as it would have were it the form of any body; because, since form and matter make one, the form must participate to some extent in the nature of that whereof it is the form.³³³³³³ἀνάγκη ἄρα, ἐπεὶ πάντα νοεῖ, ἀμίγῆ εἰναι ἳνα γνωρίζῃ· παρεμφαινόμενον γὰρ κωλύει τὸ ἀλλότριον καὶ ἀντιφράττει· διὸ οὐδὲ μεμίχθαι εὔλογον αὐτὸν τῷ σώματι (For since it understands all, it must be unmixed with any, in order to know: for any strange element coming in besides acts as an obstacle and a barrier to knowledge; therefore it is reasonable that it should not be mixed up with the body). — De anima, III, iv, 3, 4.

These passages moved Averroes³³⁴³³⁴   Abu Walid Mohammed Ibn Roschd (Averroes), called by the schoolmen ‘the Commentator,’ as Aristotle was ‘the Philosopher,’ was born at Cordova in 1120, and died in Morocco, 1198. He practised as a physician and a lawyer, and had a place about court, but was above all things a philosopher and an uncompromising Aristotelian. Fallen into neglect among his own countrymen, his philosophy embroiled the schools of Western Europe for four centuries, 1230-1630, at Paris, at Oxford, but particularly at Padua. Numerous Latin editions were printed. I shall cite the Venice edition of 1574 in the Bodleian Library, ten volumes.
   The origin of this dispute about the intellect is to be found in a passage of Plato, Theatetus, 185: “Being and not-being, likeness and unlikeness, sameness and difference, number . . . . there is no bodily organ for the cognition of these entities, but the soul by herself regards them; so it appears that the soul regards some things by herself, and other things through the bodily faculties.” This passage is the foreshadowing of the celebrated and much disputed chapters, De anima, III, iv, v. Two words there call for notice: (1) ἀπαθές, meaning unimpressed, at first hand, by matter; (2) χωριστός, separable, or separate, on which word the great contention turns. It may apply to the ‘active,’ or to the ‘potential’ intellect: but it matters not to which, for Averroes and St Thomas agree that the two go together. It may refer to the state after death, and signify that the intellectual soul is not destroyed by separation from the body: on this point again there is a general agreement between Averroes and St Thomas. The battle between them begins when the word is referred to the intellect as it is in this mortal life. St Thomas takes the term merely to mean ‘capable of operating apart from any bodily organ,’ — according to the tenor of the passage above quoted from Plato. Averroes will have it that it means, not only that, but much more than that: the meaning being according to him, that even while we live on earth, our intellect, ‘potential’ and ‘active,’ is outside of us, and is one and the same numerically for all men.
   My reading of Averroes has not revealed to me where he places this one separate universal intellect. He does not make it to be God: thus he says in his Destructio destructionum (or Refutation of the Refutations of Algazel): “If man only understood this, then his intellect would be the intellect of the God of glory; and that is false” (disp. 6, p. 87b). The notion of his day, in which he shared, that the heavenly bodies have souls, might have tempted him to place νοῦς χωριστός in some heavenly sphere: that doctrine however belongs to the disciples of Averroes, not to the master. Renan, Averroes et l’Averroisme, p. 138, gives this explanation: Une humanité vivante et permanente, tel semble donc être le sens de la théorie Averroistique de l’unité de l’intellect. L’immortalité de l’intellect actif [and of the potential intellect with it, on which Averroes chiefly insists] n’est ainsi autre chose que, la renaissance éternelle de l’humanit’, et la perpetuité de la civilisation. This interpretation derives support from Averroes’s comments on the De anima, III (pp. 149-151). Holding as he did the eternity of the world, he tells us there that the human race is eternal, and that some portion of the human race is always civilised, —positions set aside by our astronomy and geology, and at variance with the received anthropology. He says: “There must always be some philosopher amongst mankind.” I have some hesitation however in agreeing with Renan’s explanation: because this position, which he attributes to Averroes, is clearly suicidal, and the Commentator was no fool. If no individual man had a head on his shoulders, the race would be headless. Averroes (see Chap. LX) does not seem to allow to the individual man, as man, any higher faculty than a faculty proper to the sentient soul: how can a race of such sentient beings constitute an intelligence? The intelligence of the race can only mean the intelligence of this man and of that, combining to form society. But it is difficult to form any rational conception of νοῦς χωριστός as Averroes understood it. If Renan ’s interpretation be taken, then when Averroes speaks (De anima, III, p. 161) of the “active and potential intellect” as being “eternal substances,” we must understand him to call them eternal with the eternity of civilised mankind, an eternity which he positively asserts (De anima, p. 149).
   The main point of St Thomas’s attack upon the Commentator is his theory of the continuatio (ittisâl is the Arabic name, much used by the Arabian mystics), or point of contact between the universal intelligence outside and the mind of the individual man. Averroes’s words are these (De anima, II, pp. 178, 148b, 185b): “The potential intellect is not conjoined with us primarily and ordinarily: nay, it is not conjoined with us at all, except inasmuch as it is conjoined with the forms in our phantasy. . . . Since it has been shown that intellect cannot be conjoined with all men so as to be multiplied as they are multiplied, it remains that the said intellect is conjoined with us by conjunction with our intellectual impressions which are conceptions in the phantasy, that is to say, through that part of those conceptions which exists in us and serves in a manner as a form. . . . Since the impressions of speculative intellect are conjoined with us by forms of phantasy; and the active intellect is conjoined with those intellectual impressions; and the intellect which takes cognisance of those impressions, that is to say, the potential intellect, is the same [as the active]: the necessary conclusion is that the active intellect is conjoined with us by the conjunction of those intellectual impressions.” See St Thomas, Summa Theol. I, q 76 artt. 1 and 2: where he explains Averroes thus: “The Commentator says that this union is by means of the intellectual impression, which has a twofold residence, one in the potential intellect [universal, eternal, independent of the individual], and another in the impressions of phantasy, which are in the bodily organs [of the individual; in his phantasy, or sensory memory, or in the vis cogitativa, an organic faculty allied to phantasy]. And thus, through this intellectual impression, the potential intellect is continued and conjoined with the body of the individual man” (art. 1). St Thomas criticises this theory as follows (art. 2): “So long as the intellect is one, however all other things are diversified which the intellect uses as instruments, in no way can Socrates and Plato be called other than one intelligent being. . . . I grant that if the phantasm, or impression in the phantasy, inasmuch as it is other and other in you and me, were a form (or idea) of the potential intellect, then your intellectual activity and mine might be differentiated by the diversity of phantasms . . . . but the said phantasm is not a form (or idea) of the potential intellect: an idea in the potential intellect is obtained only by abstraction from phantasms. If then there were but one intellect for all men, no diversities of phantasms in this man and that could ever cause a diversity of intellectual activity between one man and another, as the Commentator pretends.”
   So far as the Averroistic Potential (and Active) Intellect can be identified with the Zeitgeist or Educated Opinion of the day, and adapted to Comte’s theory of progress, the reader will find some discussion of it in my Oxford and Cambridge Conferences, First Series, pp. 135 sq.; also Political and Moral Essays, p. 132, note.
   On De anima, III, the Commentator (p. 149) specifies three kinds of intellect: “the potential intellect, the active intellect, the acquired or made intellect: of these three, two are eternal, the active and the potential: the third is partly producible and perishable, and partly eternal.” By the ‘acquired intellect’ he appears to mean the ‘passive intellect’ of each individual, inasmuch as it is illumined by continuatio (ittisâl) with the universal potential intellect. Does that mean the mind of the individual in so far as it comes abreast of the zeitgeist? If so, but I cannot feel sure of the conclusion, then Arabian mysticism ends in positivism. to suppose the potential intellect, whereby 124the soul understands, to be separate in being from the body, and not to be the form of the body. But because this intellect would have no connexion with us, nor should we be able to understand by it unless it were somehow united with us, Averroes fixes upon a mode in which it is united with us, as he thinks, sufficiently. He says that an impression actually made in the understanding is a ‘form’ of the potential intellect, in the same way that an actually visible appearance, as such, is a ‘form’ of the visual faculty; hence out of the potential intellect, and this form or impression actually made in the same, there results one being. With whatever being therefore this ‘form’ of the understanding is conjoined, the potential intellect is also conjoined with that being. But this ‘form ‘is conjoined with us by means of the ‘phantasm,’ or image in the phantasy, which image is a Sort of subject receiving in itself that ‘form’ of understanding.

1. It is easy to see how frivolous and impossible all this construction is. For what has understanding is intelligent; and that of which an intelligible impression is united with the understanding, is understood. The fact that an intelligible impression, united with a (foreign) understanding, comes somehow to be in man, will not render man intelligent; it will merely make him understood by that separately subsisting intelligence.

2. Besides, the impression actually in understanding is the form of the potential intellect, in the same way that the actual visible appearance is the form of the visual power, or eye. But the impression actually in understanding is to the phantasms as the actual visible appearance is to the coloured surface, which is outside the soul. This similitude is used by Averroes, as also by Aristotle. Therefore the supposed union of the potential intellect (by means of the intelligible form) with the phantasm that is in us will resemble the union of the visual power with the colour that is in the stone. But this union does not make the stone see, but be seen. Therefore the aforesaid union does not make us understand, but be understood. But, plainly, it is properly and truly said that man understands: for we should not be investigating the nature 125of understanding were it not for the fact that we have understanding. The above mode of union then is insufficient.

5. The intellect in the act of understanding and the object as represented in understanding are one, as also the sense in the act of sensation and the object as represented in sense. But the understanding as apt to understand and its object as open to representation in understanding are not one, as neither is sense, so far as it is apt to have sensation, one with its object, so far as that is open to be represented in sensation.³³⁵³³⁵This aptness, openness, or potentiality, is precisely what idealists ignore. They will have every thing actual. The impression made by the object, so far as it lies in images of the phantasy, is not any representation in the understanding. Only by undergoing a process of abstraction from such images does the impression became one with the intellect in the act of understanding. In like manner the impression of colour is actually felt in sense, not as it is in the stone, but as it is in the eye. Now, on the theory of Averroes, the intelligible form, or impression in the understanding, only comes to be conjoined with us by finding place in the images of our phantasy. Therefore it is not conjoined with us inasmuch as it is one with the potential intellect, being its form. Therefore it cannot be the medium whereby the potential intellect is conjoined with us: because, in so far as it is conjoined with the potential intellect, it is not conjoined with us; and in so far as it is conjoined with us, it is not conjoined with the potential intellect.