[191] Aristot. Physica, VII. iii. p. 247, b. 9: ἡ δ’ ἐξ ἀρχῆς λῆψις τῆς ἐπιστήμης γένεσις οὐκ ἔστιν· τῷ γὰρ ἠρεμῆσαι καὶ στῆναι τὴν διάνοιαν ἐπίστασθαι καὶ φρονεῖν λέγομεν. — Also De Animâ, I. iii. p. 407, b. 32, and the remarkable passage in the Analytica Poster. II. xviii. p. 100, a. 3-b. 5.
Passing now to the Emotions, we find that these are not systematically classified and analysed by Aristotle, as belonging to a scheme of Psychology; though he treats them incidentally, with great ability and acuteness, both in his Ethics, where he regards them as auxiliaries or impediments to a rational plan of life, and in his Rhetoric, where he touches upon their operation as it bears on oratorical effect. He introduces however in his Psychology some answer to the question, What is it that produces local movement in the animal body? He replies that movement is produced both by Noûs and by Appetite.
Speaking strictly, we ought to call Appetite alone the direct producing cause, acted upon by the appetitum, which is here the Primum Movens Immobile. But this appetitum cannot act without coming into the intellectual sphere, as something seen, imagined, cogitated.[192] In this case the Noûs or Intellect is stimulated through appetite, and operates in subordination thereto. Such is the Intellect, considered as Practical, the principle or determining cause of which is the appetitum or object of desire; the Intellect manifesting itself only for the sake of some end, to be attained or avoided. Herein it is distinguished altogether from the Theoretical Noûs or Intellect, which does not concern itself with any expetenda or fugienda and does not meddle with conduct. The appetitum is good, real or apparent, in so far as it can be achieved by our actions. Often we have contradictory appetites; and, in such cases, the Intellect is active generally as a force resisting the present and caring for the future. But Appetite or Desire, being an energy including both soul and body, is the real and appropriate cause that determines us to local movement, often even against strong opposition from the Intellect.[193]
[192] Aristot. De Animâ, III. x. p. 433, b. 11: πρῶτον δὲ πάντων τὸ ὀρεκτόν (τοῦτο γὰρ κινεῖ οὐ κινούμενον τῷ νοηθῆναι ἢ φαντασθῆναι).
[193] Aristot. De Animâ, III. x. p. 433, a. 25, b. 19: διὸ ἐν τοῖς κοινοῖς σώματος καὶ ψυχῆς ἔργοις, &c.
Aristotle thus concludes his scheme of Psychology, comprehending all plants as well as all animals; a scheme differing in this respect, as well as in others, from the schemes of those that had preceded him, and founded upon the peculiar principles of his own First Philosophy. Soul is to organized body as Form to Matter, as Actualizer to the Potential; not similar or homogeneous, but correlative; the two being only separable as distinct logical points of view in regard to one and the same integer or individual. Aristotle recognizes many different varieties of Soul, or rather many distinct functions of the same soul, from the lowest or most universal, to the highest or most peculiar and privileged; but the higher functions presuppose or depend upon the lower, as conditions; while the same principle of Relativity pervades them all. He brings this principle prominently forward, when he is summing up[194] in the third or last book of the treatise De Animâ:—“The Soul is in a certain way all existent things; for all of them are either Perceivables or Cogitables; and the Cogitant Soul is in a certain way the matters cogitated, while the Percipient Soul is in a certain way the matters perceived.� The Percipient and its Percepta — the Cogitant and its Cogitata — each implies and correlates with the other: the Percipient is the highest Form of all Percepta; the Cogitant is the Form of Forms, or the highest of all Forms, cogitable or perceivable.[195] The Percipient or Cogitant Subject is thus conceived only in relation to the Objects perceived or cogitated, while these Objects again are presented as essentially correlative to the Subject. The realities of Nature are particulars, exhibiting Form and Matter in one: though, for purposes of scientific study — of assimilation and distinction — it is necessary to consider each of the two abstractedly from the other.
[194] Ibid. viii. p. 431, b. 20, seq.: νῦν δὲ περὶ ψυχῆς τὰ λεχθέντα συγκεφαλαιώσαντες, εἴπωμεν πάλιν ὅτι ἡ ψυχὴ τὰ ὄντα πώς ἐστι πάντα. ἢ γὰρ αἰσθητὰ τὰ ὄντα ἢ νοητά, ἔστι δὲ ἡ ἐπιστήμη μὲν τὰ ἐπιστητά πως, ἡ δ’ αἴσθησις τὰ αἰσθητά.
[195] Ibid. p. 432, a. 2: ὁ νοῦς εἶδος εἰδῶν, καὶ ἡ αἴσθησις εἶδος αἰσθητῶν.