 There is disagreement over the rest of the formulation Proclus attributes to Xenocrates: in speaking of ‘the things that are always constituted according to nature’, did Xenocrates intend to rule out forms for individuals, which are transitory, and for artefacts, which are not constituted according to nature? This is the way Proclus goes on to interpret Xenocrates, and it is hard to see how to get around that, although attempts have been made (see Cherniss 1944 [1962], 256). But there is indirect confirmation of Proclus’ interpretation, at least where artefacts are concerned, from Clement of Alexandria, who tells us (in Stromateis II 5) that Xenocrates claimed that knowledge of the intelligible substance is theoretical as opposed to practical ‘judgment’; at that rate, carpenters are not contemplating forms when they make beds and shuttles, despite what is said by Plato in Republic X 596b and Cratylus 389a–b, and (if it is by Plato) Letter vii 342d. But it should be noted that the rejection of forms for artefacts is in agreement with what Aristotle has to say about Plato and Platonists in Metaphysics I 9. 991b6–7, XII 3. 1070a13–19, and in the fragmentary remains of On Ideas in Alexander (see esp. Hayduck 1891, 79.23–24, 80.6). Likewise the rejection of forms for individuals squares with Aristotle’s attack on the ‘argument from thinking’ (Metaphysics I 9. 990b14–15 = XIII 4. 1079a10–11, supplemented by Alexander, Hayduck 1891, 81.25–82.7): if every object of thought is a form, then there are forms also “for the perishables” (990b14 = 1079b10) or “for the particulars and perishables, such as Socrates, Plato” (Alexander, Hayduck 1891, 82.2–3).