Page - 178 - in The Priority of Locomotion in Aristotle’s Physics

responsible for all of the relevant alteration, because it is responsible for perception, is not sufficient. In addition, perception is not the process one typically thinks about when speaking about alterations that occur in living things, and indeed it is not characterized as a full-blooded alteration, but merely as a sort of (ἀλλοίωσις τις).31 The relation between the cause of the change, i.e. the sensory part, and that which undergoes the change differs significantly from the relation between the cause of an animal’s change in place and quantity. For the argument to work, however, there must be a part of the soul that is responsible for certain alterations that occur in the animal in the same way that such a part exists for the other two kinds of change. That this is what Aristotle has in mind becomes clear in a passage in De Partibus Animalium I 1, in which he points out which of the parts is responsible for alteration.32 In this text Aristotle says explicitly that the three kinds of non-substantial change (of which the living thing itself is the source) are caused not by the whole of the soul, but rather by one specific part.33 In accordance with the De Anima this passage also presents “the part which is present even in plants”, i.e. the nutritive part, as the origin (ἀρχή) of growth (and diminution).34 It has the capacity to change nourishment into (blood and) flesh and in this way makes it possible for the nourishment to be assimilated into the body in the process of growth.35 According to PA I 1, the perceptive part of the soul (αἰσθητικόν) is the origin (ἀρχή) of alteration in a living being.36 This is far from self-evident. It seems that, for Aristotle, an alteration, for instance the case in which I get a tan, is caused by this part of the soul in the following way.37 The sensory part receives some input and reacts by initiating the respective change: in the example, the sun’s shining on my skin alone does not make the colour of my skin change; this only happens if the sensory part of my soul, having 31 ἡ μὲν γὰρ αἴσθησις ἀλλοίωσις τις εἶναι δοκεῖ, de An. II 4, 415b24. 32 The passage, found in PA I 1, 641b4–8, as a whole is: ἢ οὐκ ἔστι πᾶσα ἡ ψυχὴ κινή- σεως ἀρχή, οὐδὲ τὰ μόρια ἅπαντα, ἀλλ᾽ αὐξήσεως μὲν ὅπερ καὶ ἐν τοῖς φυτοῖς, ἀλλοιώσεως δὲ τὸ αἰσθητικόν, φορᾶς δ᾽ ἕτερόντι καὶ οὐ τὸ νοητικόν: “However, it is not the case that all soul is an origin of change, nor all its parts; rather of growth the origin is the part which is present even in plants, of alteration the perceptive part, and of locomotion some other part, and not the rational” (Transl. Lennox (2001)). 33 ἢ οὐκ ἔστι πᾶσα ἡ ψυχὴ κινήσεως ἀρχή, οὐδὲ τὰ μόρια ἅπαντα, PA I 1, 641b4–5. 34 ἀλλ᾽ αὐξήσεως μὲν ὅπερ καὶ ἐν τοῖς φυτοῖς, PA I 1, 641b6. 35 For the process of growth see GC I 5 and de An. II 4. For my understanding of the pro- cess of growth see section 3.2.1 in my discussion of the first argument for the priority of loco- motion, where the relevant passages in Aristotle are discussed. 36 ἀλλοιώσεως δὲ τὸ αἰσθητικόν, PA I 1, 641b6–7. 37 For this see Balme (1992), 91–92, on whose interpretation of this passage from PA I 1 my understanding of it is based. 178 Locomotion is prior in essence ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen