SOUL AND MIND penetrates our ears If perception is to take place, the pores and the eZuences have to match each other (DK 31 A86) This matching must, of course, take place at the level of the elements, the fundamental principles of explanation in Empedocles’ system In some cases this is simple: sound is carried by air, which is echoed by the air in the inner ear In the case of sight it is more complicated, and must be a matter of the proportions of each of the elements, as suggested in the fragment above The most complex mixture of all the elements is blood, and as the blood churns round the heart this produces thought The reWned nature of the blood’s constitution is what explains the wide-ranging nature of thought (DK 31 B105, 107) The crude nature of Empedocles’ materialism made him easy game for later philosophers of mind Aristotle complained that he had not distinguished between perception and thought Others pointed out that other things besides eyes and ears had pores: why then were sponges and pumices not capable of perception? The atomist Democritus oVered an answer to this question The visual image was the product of an interaction between eZuences from the seen object and eZuences from the person seeing: this image or impression was formed in the intervening air, and then entered the pupil of the eye (KRS 589) But Democritus, like Empedocles, was unable to oVer any remotely convincing account of thought, and so, like him, fell foul of Aristotle’s criticism The Presocratic whom later Greeks revered as a philosopher of mind was Anaxagoras Anaxagoras believed that the universe began as a tiny complex unit which expanded and evolved into the world we know, but that at every stage of evolution every single thing contains a portion of everything else This development is presided over by Mind (nous), which is itself outside the evolutionary process Other things have a portion of everything, but Mind is unlimited and independent and is unmixed with any kind of stuV, but stands all alone by itself For if it was not by itself, but was mixed with anything else, it would have a share in every kind of stuV, since as I said earlier in everything there is a portion of everything The things mixed with it would prevent it from controlling everything in the way it does now when it is alone by itself For it is the Wnest and purest of all things, and it has all knowledge of and all power over everything All things that have souls, the greater and the lesser, are governed by Mind (KRS 476) 233