I have called this principle, by which each slight variation, if useful, is preserved, by the term Natural Selection.
译文:我本来是一介平民,在南阳务农亲耕,只想在乱世中苟且保全性命,不谋求在诸侯之中闻名显达。
You can't change your elephant by direct force, but you can train it over time.