I do not ... reject the use of statistics in medicine, but I condemn not trying to get beyond them and believing in statistics as the foundation of medical science. ... Statistics ... apply only to cases in which the cause of the facts observed is still [uncertain or] indeterminate. ... There will always be some indeterminism ... in all the sciences, and more in medicine than in any other. But man's intellectual conquest consists in lessening and driving back indeterminism in proportion as he gains ground for determinism by the help of the experimental method.

But while I accept specialization in the practice, I reject it utterly in the theory of science.

The experimenter who does not know what he is looking for will not understand what he finds.

The great experimental principle, then, is doubt, that philosophic doubt which leaves to the mind its freedom and initiative, and from which the virtues most valuable to investigators in physiology and medicine are derived.

The better educated we are and the more acquired information we have, the better prepared shall we find our minds for making great and fruitful discoveries.

When we meet a fact which contradicts a prevailing theory, we must accept the fact and abandon the theory, even when the theory is supported by great names and generally accepted.

Well-observed facts, though brought to light by passing theories, will never die; they are the material on which alone the house of science will at last be built.