In every province of human knowledge where we now possess a careful
and coherent interpretation of nature, men began by attempting in
bold flights to leap from obvious facts to the highest point of
generality--to some wide and simple principle which after-ages had to
reject. Thus, from the facts that all bodies are hot or cold, moist or
dry, they leapt at once to the doctrine that the world is constituted
of four elements--earth, air, fire, water; from the fact that the
heavenly bodies circle the sky in courses which occur again and again,
they at once asserted that they move in exact circles, with an exactly
uniform motion; from the fact that heavy bodies fall through the air
somewhat faster than light ones, it was assumed that all bodies fall
quickly or slowly exactly in proportion to their weight; from the fact
that the magnet attracts iron, and that this force of attraction is
capable of increase, it was inferred that a perfect magnet would have
an irresistible force of attraction, and that the magnetic pole of
the earth would draw the nails out of a ship’s bottom which came near
it; from the fact that some of the finest quartz crystals are found
among the snows of the Alps, it was inferred that the crystallisation
of gems is the result of intense and long-continued cold: and so on
in innumerable instances. Such anticipations as these constituted
the basis of almost all the science of the ancient world; for such
principles being so assumed, consequences were drawn from them with
great ingenuity, and systems of such deductions stood in the place of
science.--_Edinburgh Review_, No. 216.