It was not until the time of Shakespeare himself that another spirit began to assert itself--namely, that of asking whether a prevalent belief or tradition is actually a true statement of fact. Men proceeded to test the belief by an examination of the thing in question, and not by merely adducing the assertions of "the learned so-and-so," or of "the ingenious Mr. Dash." This spirit of inquiry actually existed in a fairly active state among the more cultivated of the ancient Greeks. Aristotle (who flourished about 350 B.C.), though he could not free himself altogether from the primitive tendency to accept the marvellous as true because it is marvellous and without regard to its probability--in fact because of its improbability--yet on the whole showed a determination to investigate, and to see things for himself, and left in his writings an immense series of first-rate original observations. He had far more of the modern scientific spirit than had the innumerable credulous writers of Western Europe who lived fifteen hundred to two thousand years after him. Even that delightful person Herodotus, who preceded Aristotle by a hundred years, occasionally took the trouble to inquire into some of the wonders he heard of on his travels, and is careful to say now and then that he does not believe what he heard. But the mediaeval-makers of "bestiaries," herbals, and treatises on stones, which were collections of every possible fancy and "old-wife's tale," about animals, plants, and minerals, mixed up with Greek and Arabic legends and the mystical, medical lore of the "Physiologus"--that Byzantine cyclopaedia of "wisdom while you wait"--deliberately discarded all attempt to set down the truth; they simply gave that up as a bad job, and recorded every strange story, property and "application" (as they termed it) of natural objects with solemn assurance, adding a bit of their own invention to the gathered and growing mass of preposterous misunderstanding and superstition.