Silliman Foundation, was immediately turned in to the Yale University
Press for publication. Duly set in type, proofs in galley form had been
submitted to him and despite countless interruptions he had already
corrected and revised a number of the galleys when the great war came.
But with the war on, he threw himself with energy and devotion into
the military and public duties which devolved upon him and so never
completed his proof-reading and intended alterations. The careful
corrections which Sir William made in the earlier galleys show that the
lectures were dictated, in the first instance, as loose memoranda for
oral delivery rather than as finished compositions for the eye, while
maintaining throughout the logical continuity and the engaging con moto
which were so characteristic of his literary style. In revising the
lectures for publication, therefore, the editors have merely endeavored
to carry out, with care and befitting reverence, the indications
supplied in the earlier galleys by Sir William himself. In supplying
dates and references which were lacking, his preferences as to editions
and readings have been borne in mind. The slight alterations made, the
adaptation of the text to the eye, detract nothing from the original
freshness of the work.

In a letter to one of the editors, Osler described these lectures as "an
aeroplane flight over the progress of medicine through the ages." They
are, in effect, a sweeping panoramic survey of the whole vast field,
covering wide areas at a rapid pace, yet with an extraordinary variety
of detail. The slow, painful character of the evolution of medicine from
the fearsome, superstitious mental complex of primitive man, with his
amulets, healing gods and disease demons, to the ideal of a clear-eyed
rationalism is traced with faith and a serene sense of continuity. The
author saw clearly and felt deeply that the men who have made an idea or
discovery viable and valuable to humanity are the deserving men; he