r progress in moral and political philosophy has
been sometimes contrasted with their supposed failure in physical
investigations. 'They had plenty of ideas,' says Dr. Whewell, 'and
plenty of facts; but their ideas did not accurately represent the facts
with which they were acquainted.' This is a very crude and misleading
way of describing ancient science. It is the mistake of an uneducated
person--uneducated, that is, in the higher sense of the word--who
imagines every one else to be like himself and explains every other age
by his own. No doubt the ancients often fell into strange and fanciful
errors: the time had not yet arrived for the slower and surer path of
the modern inductive philosophy. But it remains to be shown that they
could have done more in their age and country; or that the contributions
which they made to the sciences with which they were acquainted are not
as great upon the whole as those made by their successors. There is no
single step in astronomy as great as that of the nameless Pythagorean
who first conceived the world to be a body moving round the sun in
space: there is no truer or more comprehensive principle than the
application of mathematics alike to the heavenly bodies, and to the
particles of matter. The ancients had not the instruments which would
have enabled them to correct or verify their anticipations, and their
opportunities of observation were limited. Plato probably did more
for physical science by asserting the supremacy of mathematics than
Aristotle or his disciples by their collections of facts. When the
thinkers of modern times, following Bacon, undervalue or disparage the
speculations of ancient philosophers, they seem wholly to forget the
conditions of the world and of the human mind, under which they
carried on their investigations. When we accuse them of being under the
influence of words, do we suppose that we are altogether free from this
illusion? When we remark that Greek physics soon became stationary or
extinct, may we not observe also that there have been and may be again
periods in the history of modern philosophy which have been barren and
unproductive? We might as well maintain that Greek art was not real
or great, because it had nihil simile aut secundum, as say that Greek
physics were a failure because they admire no subsequent progress.

The charge of premature generalization which is often urged against
ancient philosophers is really an anachronism. For they ca