of philosophy find in Plato "the
greatest thinker and writer of all time."(1) The student of science
must recognize in him a thinker whose point of view was essentially
non-scientific; one who tended always to reason from the general to
the particular rather than from the particular to the general. Plato's
writings covered almost the entire field of thought, and his ideas
were presented with such literary charm that successive generations
of readers turned to them with unflagging interest, and gave them wide
currency through copies that finally preserved them to our own time.
Thus we are not obliged in his case, as we are in the case of every
other Greek philosopher, to estimate his teachings largely from hearsay
evidence. Plato himself speaks to us directly. It is true, the literary
form which he always adopted, namely, the dialogue, does not give quite
the same certainty as to when he is expressing his own opinions that
a more direct narrative would have given; yet, in the main, there is
little doubt as to the tenor of his own opinions--except, indeed, such
doubt as always attaches to the philosophical reasoning of the abstract
thinker.

What is chiefly significant from our present standpoint is that the
great ethical teacher had no significant message to give the world
regarding the physical sciences. He apparently had no sharply defined
opinions as to the mechanism of the universe; no clear conception as to
the origin or development of organic beings; no tangible ideas as to
the problems of physics; no favorite dreams as to the nature of matter.
Virtually his back was turned on this entire field of thought. He was
under the sway of those innate ideas which, as we have urged, were among
the earliest inductions of science. But he never for a moment suspected
such an origin for these ideas. He supposed his conceptions of being,
his standards of ethics, to lie back of all experience; for him they
were the most fundamental and most dependable of facts. He criticised
Anaxagoras for having tended to deduce general laws from observation. As
we moderns see it, such criticism is the highest possible praise. It is
a criticism that marks the distinction between the scientist who is also
a philosopher and the philosopher who has but a vague notion of physical
science. Plato seemed, indeed, to realize the value of scientific
investigation; he referred to the astronomical studies of the Egyptians
and Chaldeans, and spoke hopefull