t, his
mind was not overloaded with the medical theories of his own time.
Cusanus was probably not more than thirty when he made the suggestion
which represents the first practical hint for the use of laboratory
methods in modern medicine. It came out of his thoughtful consideration
of medical problems rather than from a store of garnered information as
to what others thought. It is a lesson in the precious value of breadth
of education and serious training of mind for real progress at all
times.

XIV

BASIL VALENTINE, LAST OF THE ALCHEMISTS, FIRST OF THE CHEMISTS

"Fieri enim potest ut operator erret et a via regia deflectat,
sed ut erret natura quando recte tractatur fieri non potest."

"For it is quite possible that the physician should err and be
turned aside from the straight (royal) road, but that nature
when she is rightly treated should err is quite impossible."

This is one of the preliminary maxims of a treatise on medicine written
by a physician born not later than the first half of the fifteenth
century, and who may have lived even somewhat earlier. We are so prone
to think of the men of that time as utterly dependent on authority, not
daring to follow their own observation, suspecting nature, and almost
sure to be convinced that only by going counter to her could success in
the treatment of disease be obtained, that it is a surprise to most
people to find how completely the attitude of mind, that is supposed to
be so typically modern in this regard, was anticipated full four
centuries ago. There are other expressions of this same great physician
and medical writer, Basil Valentine, which serve to show how faithfully
he strove with the lights that he had to work out the treatment of
patients, just as we do now, by trying to find out nature's way, so as
to imitate her beneficent processes and purposes. It is quite clear
that he is but one of many faithful, patient observers and
experimenters--true scientists in the best sense of the word--who lived
in all the centuries of the Middle Ages.

Speculations and experiments with regard to the elixir of life, the
philosopher's stone, and the transmutation of metals, are presumed to
have filled up all the serious interests of the alchemists, supposed to
be almost the only scientists of those days. As a matter of fact,
however, men were making original observations of profound significance,
and these were considered so valuable