To them that ask thee, Where hast thou seen the Gods, or how knowest thou certainly that there be Gods, that thou art so devout in their worship? I answer first of all, that even to the very eye, they are in some manner visible and apparent. Secondly, neither have I ever seen mine own soul, and yet I respect and honour it. So then for the Gods, by the daily experience that I have of their power and providence towards myself and others, I know certainly that they are, and therefore worship them.