taste is, what touch is, what smell is, and how it is that you exercise the energies of each of these faculties; and what the sources of them are from which they originate. (138) For do not tell me long stories about the moon and the sun, and all the other things in heaven and in the world, which are at such a distance from us and which are so different in their natures, empty-minded creatures that you are, before you examine into and become acquainted with yourselves; for when you have learnt to understand yourselves, then perhaps one may believe you when you enter into explanations respecting other things. But till you are able to tell what you yourselves are, do not expect ever to be looked upon as truth-telling judges or witnesses with respect to others.