 Aristotle complains in 1080b28–30 that on Xenocrates’ view it is not so that every two units make up a pair, and also that on his view not every geometrical magnitude divides into smaller magnitudes. This has to do with Xenocrates’ acceptance of the idea that there are indivisible lines; this idea Aristotle ascribes to Plato in Metaphysics I 9. 992a20–22, and Alexander’s commentary on that passage adds the name Xenocrates, in a way that suggests that Xenocrates’ acceptance of indivisible magnitudes was even better known than Plato’s (Hayduck 1891, 120.6–7; see also Simplicius on De caelo, Heiberg 1894, 563.21–22 and many other passages in the commentators in which this ascription occurs: frs. 41–49H, 123–147IP). As Proclus understood Xenocrates’ position, it applied to the Form of the line rather than to geometrical or physical magnitudes (see Diehl 1904, 245.30–246.4), but this is very much a minority view: Porphyry is quoted by Simplicius in the latter’s commentary on the Physics (Diels 1882, 140.9–13) as saying that, according to Xenocrates, what is: