None of those who maintained that the universe is a unity achieved any conception of this type of cause, except perhaps Parmenides Founder of the above; fl. about 475. ; and him only in so far as he admits, in a sense, not one cause only but two. i.e. in the Δόξα . Parmenides Fr. 8 (Diels) ; R.P. 121. But those who recognize more than one entity, e.g. hot and cold, or fire and earth, are better able to give a systematic explanation, because they avail themselves of fire as being of a kinetic nature, and of water, earth, etc., as being the opposite. Aristotle is probably thinking of Empedocles. Cf. Aristot. Met. 4.8 . After these thinkers and the discovery of these causes, since they were insufficient to account for the generation of the actual world, men were again compelled (as we have said) by truth itself to investigate the next first principle. For presumably it is unnatural that either fire or earth or any other such element should cause existing things to be or become well and beautifully disposed; or indeed that those thinkers should hold such a view. Nor again was it satisfactory to commit so important a matter to spontaneity and chance. Hence when someone Anaxagoras. said that there is Mind in nature, just as in animals, and that this is the cause of all order and arrangement, he seemed like a sane man in contrast with the haphazard statements of his predecessors. Cf. Plat. Phaedo 97b-98b . We know definitely that Anaxagoras adopted this view; but Hermotimus A semi-mythical person supposed to have been a preincarnation of Pythagoras. of Clazomenae is credited with having stated it earlier. Those thinkers, then, who held this view assumed a principle in things which is the cause of beauty, and the sort of cause by which motion is communicated to things.