not be said that Vital Principle is derived from them all ? Now, there do not appear to be any elements which are common to all the categories. Shall it then be formed only from such elements as pertain to the essence? How, in that case, is it to recognise each of the others? Shall it be said that there are, for each genus, elements and peculiar principles wherewith the Vital Principle may be formed? If so, it will be quantity, and quality and essence; but it is impossible that from the elements of quantity there should be eliminated essence without quantity.
Such and other such difficulties concur to oppose the opinion of those who say that the Vital Principle is formed from all the elements.
It is absurd to maintain that like is unimpressionable by like, and yet assert that like is able to perceive and recognise like by like; and the more so, as these writers set down feeling as they do thinking and recognising, as some kind of impression and motion. But to shew how many doubts and difficulties beset the opinion adopted by Empedocles, that "objects are recognised by the corporeal elements in the relation of like;" we have only to observe that all those parts in animal bodies, which are simply of earth, as bones, sinews and hairs, seem to be altogether without feeling, and consequently without any feeling of like, and yet, according to the theory, they