In 1992 Myles Burnyeat published an essay he entitled ‘Is an Aristotelian philosophy of mind still credible?’, labelling it ‘A draft’. As he stated, he did so ‘with reluctance’. He had intended it as a working paper only, ‘to provoke discussion’. It had provoked not just discussion and as much lively interest as anything he ever wrote, but attempted refutations in print. Hence his own reluctant eventual decision for publication. Many have regretted that in Volumes i and ii of Explorations he included neither this nor a closely connected article, published in its final English version in 1995 as ‘How much happens when Aristotle sees red and hears middle C? Remarks on De Anima 2, 7–8’. But as Burnyeat had intended, he continued to work on refining and developing his interpretation of Aristotle’s theory of perception, and the main result was the major extended essay of 2002 on De Anima ii.5, reprinted here in Part i as Chapter 5 (in which he also comments on those earlier publications). Chapter 6 is an allied treatment of the same topic in Aquinas’s writings.