After all he might have been happier in geology or physics; or in business, a small tobacco shop perhaps. But he could not add, and he distrusted rocks and atoms. The very notion of the past now filled him with horror: there was no end to it. Even at the marge of sapience, back past the start of language, of will, of men and halfmen, their damned artifacts, their garbage, their tortuous ascent, down on his knees sifting the shit of a gone age, searching for the philosopher's stone that had changed humus to homo and feces to species.