A failure is not always a mistake, it may simply be the best one can do under the circumstances. The real mistake is to stop trying.
B. F. SkinnerThe evolution of cultures appears to follow the pattern of the evolution of species. The many different forms of culture which arise correspond to the "mutations" of genetic theory. Some forms prove to be effective under prevailing circumstances and others not, and the perpetuation of the culture is determined accordingly.
B. F. SkinnerA first principle not formally recognized by scientific methodologists: when you run into something interesting, drop everything else and study it.
B. F. Skinner