A knowledge of medicine was destined to correct that defect, and we shall mark the growth of its most precious fruits in the increased power of observation and the counterpoise it offered to hasty generalizations, as well as in the confidence which learnt to reject untenable fictions, whether produced by luxuriant imagination or by a priori speculations, on the similar ground of self-reliant sense-perception."(3) (3) Gomperz: Greek Thinkers, Vol.

I, p.

276.
The nature philosophers of the Ionian days did not contribute much to medicine proper, but their spirit and their outlook upon nature influenced its students profoundly.

Their bold generalizations on the nature of matter and of the elements are still the wonder of chemists.
We may trace to one of them, Anaximenes, who regarded air as the primary principle, the doctrine of the "pneuma," or the breath of life--the psychic force which animates the body and leaves it at death--"Our soul being air, holds us together." Of another, the famous Heraclitus, possibly a physician, the existing fragments do not relate specially to medicine; but to the philosopher of fire may be traced the doctrine of heat and moisture, and their antitheses, which influenced practice for many centuries.

There is evidence in the Hippocratic treatise peri sarkwn of an attempt to apply this doctrine to the human body.