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 on change
We must, however, acknowledge, as it seems to me, that man with all his noble qualities...still bears in his bodily frame the indelible stamp of his lowly origin. Charles Darwin on darwinism
In the survival of favoured individuals and races, during the constantly-recurring struggle for existence, we see a powerful and ever-acting form of selection. Charles Darwin on nature