Page - 102 - in The Priority of Locomotion in Aristotle’s Physics

sation and rarefaction. There he says that “the dense is the heavy, and the rare the light.”77 This, of course, does not mean that something merely by undergoing rarefaction or condensation changes with respect to its weight, although this passage has been read that way.78 This indeed would be absurd. Rather, what he obviously intends to say here is that there is a con- nection between a thing’s density and its weight, because when comparing two things with respect to their weight their density matters. As Aristotle points out in Cael. III 1, of two things that have the same volume that which is of higher density is heavier than the other, since there is “more in the same material bulk.”79 In this sense a state of density or rarity may be assigned to heaviness or lightness. In Phys. IV 9 Aristotle adds that basically the dense not only seems to be associated with the heavy, but also with the hard (σκληρόν), while the rare (that is, the opposite of dense) he associates with the light, but also with the soft (μαλακόν).80 That this is plausible is clear from the following example. Suppose, I want to produce a statue from a lump of bronze. In order to do so I heat the bronze; it expands, i.e. becomes less dense, looses its hardness more and more until, at a certain point, it even turns liquid, which allows me to pour it into the statue’s form. In cooling, the bronze contracts, becomes denser and hard again. So far, this understanding of Aristotle’s claim matches perfectly with what is said in the second argument for the priority of locomotion, since four of the qualities mentioned there—namely heavy, light, hard, and soft— are clearly assigned to states of density and rarity in Phys. IV 9, which paral- lels their characterisation as forms of density and rarity (πυκνότητες καὶ ἀραιότητες) in Phys. VIII 7.81 Thus, what he seems to have in mind is that when something changes in respect of quality a change in density is some- how involved. Since having a certain density corresponds to having certain qualities, a change in the density of x, that is condensation or rarefaction, implies a change in x’s qualities. In this sense an alteration would always go hand in hand with a change in density. 77 ἔστι δὲ τὸ μὲν πυκνὸν βαρύ, τὸ δὲ μανὸν κοῦφον. Phys. IV 9, 217b11–12. 78 This seems to be the view held by Graham (1999),123, who takes the alleged falsity of this view as another reason for claiming that Aristotle does not present his own view any- where in the argument. 79 Ἔτι εἰ τὸ μὲν βαρὺ πυκνόν τι, τὸ δὲ κοῦφον μανόν, ἔστι δὲ πυκνὸν μανοῦ δια- φέρον τῷ ἐν ἴσῳ ὄγκῳ πλεῖον ἐνυπάρχειν, Cael. III 1, 299b7–9: “Again, suppose that what is heavy is a dense body, and what is light rare. Dense differs from rare in containing more matter in the same bulk.” (Transl. Stocks). 80 See Phys. IV 9, 217b16–18. 81 Therefore Graham (1999) is wrong when he claims that “nowhere in his physical the- ory” does Aristotle account “for basic qualities in terms of condensation and rarefaction” (122). 102 Locomotion necessarily accompanies each of the other kinds of change ISBN Print: 9783525253069 — ISBN E-Book: 9783647253060 © 2014, Vandenhoeck & Ruprecht GmbH & Co. KG, Göttingen