In using lysergic acid or psilocybin, I usually start with some such theme as polarity, transformation (as of food into organism), competition for survival, the relation of the abstract to the concrete, or of Logos to Eros, and then allow my heightened perception to elucidate the theme in terms of certain works of art or music, of some such natural object as a fern, a flower, or a sea shell, of a religious or mythological archetype (it might be the Mass), and even of personal relationships with those who happen to be with me at the time. Or I may concentrate upon one of the senses and try, as it were, to turn it back upon itself so as to see the process of seeing, and from this move on to trying to know knowing, so approaching the problem of my own identity. - by Alan Watts
