History shows that the human mind, fed by constant accessions of knowledge,
periodically grows too large for its theoretical coverings, and bursts
them asunder to appear in new habiliments, as the feeding and growing
grub, at intervals, casts its too narrow skin and assumes another...
Truly the imago state of Man seems to be terribly distant, but every
moult is a step gained.
-- Charles Darwin, from "Origin of the Species"