It has been a long time since anyone knew everything. In the Middle Ages there were any number of friars, like Vincent of Beauvais, who had absorbed more or less all that could be gotten from books; the jottings of these saintly polymaths once filled the libraries of Europe. The handful of things that Sir Thomas Browne could not discover in the numerous volumes he owned or consulted over the course of his long life he found out for himself by experiment — that "a Cocks egg hatched under a Toad or Serpent" does not produce a basilisk, for example.