Book 4
9
And further they say that many of the animals as well get from the same things impressions which are contrary to ours, and that the individual himself does not always think the same in matters of sense-perception. Thus it is uncertain which of these impressions are true or false; for one kind is no more true than another, but equally so. And hence Democritus saysCf. Ritter and Preller, 204. that either there is no truth or we cannot discover it.
10
And in general it is because they suppose that thought is sense-perception, and sense-perception physical alteration, that they say that the impression given through sense-perception is necessarily true; for it is on these grounds that both Empedocles and Democritus and practically all the rest have become obsessed by such opinions as these.
11
For Empedocles says that those who change their bodily condition change their thought:
11
For according to that which is present to them doth thought increase in men.Empedocles Fr. 106.
11
And in another passage he says:
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And as they change into a different nature, so it ever comes to them to think differently.Empedocles Fr. 108.
12
And Parmenides too declares in the same way:
12
For as each at any time hath the temperament of his many-jointed limbs, so thought comes to men. For for each and every man the substance of his limbs is that very thing which thinks; for thought is that which preponderates.Empedocles Fr. 16; quoted also (in a slightly different form; see critical notes) by Theophrastus, De Sensu 3.
