The eloquence of a scientist is clarity; scientific truth is always more luminous when its beauty is unadorned than when it is tricked out in the embellishments with which our imagination would seek to clothe it.

First causes are outside the realm of science.

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.

Tout est poison, rien n'est poison, tout est une question de dose. Everything is poisonous, nothing is poisonous, it is all a matter of dose.

The first requirement in using statistics is that the facts treated shall be reduced to comparable units.

Men who have excessive faith in their theories or ideas are not only ill prepared for making discoveries; they also make very poor observations. Of necessity, they observe with a preconceived idea, and when they devise an experiment, they can see, in its results,only a confirmation of their theory. In this way they distort observation and often neglect very important facts because they do not further their aim.

Men who believe too firmly in their theories, do not believe enough in the theories of others. So ... these despisers of their fellows ... make experiments only to destroy a theory, instead of to seek the truth.