“The fact that knowledge endlessly recedes as the investigator is about to grasp it is what constitutes at the same time his torment and happiness.”

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

We achieve more than we know. We know more than we understand. We understand more than we can explain.

The stability of the internal medium is a primary condition for the freedom and independence of certain living bodies in relation to the environment surrounding them.

We must never make experiments to confirm our ideas, but simply to control them.

We must keep our freedom of mind, and must believe that in nature what is absurd, according to our theories, is not always impossible.

The goal of scientific physicians in their own science … is to reduce the indeterminate. Statistics therefore apply only to cases in which the cause of the facts observed is still indeterminate.

Science admits no exceptions; otherwise there would be no determinism in science, or rather, there would be no science.

Mediocre men often have the most acquired knowledge. It is in the darker. It is in the darker regions of science that great men are recognized; they are marked by ideas which light up phenomena hitherto obscure and carry science forward.

Experiment is fundamentally only induced observation.

The science of life is a superb and dazzlingly lighted hall which may be reached only by passing through a long and ghastly kitchen.

Our ideas are only intellectual instruments which we use to break into phenomena; we must change them when they have served their purpose, as we change a blunt lancet that we have used long enough.

Now, a living organism is nothing but a wonderful machine endowed with the most marvellous properties and set going by means of the most complex and delicate mechanism.

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.

In science, the best precept is to alter and exchange our ideas as fast as science moves ahead.

We must remain, in a word, in an intellectual disposition which seems paradoxical, but which, in my opinion, represents the true mind of the investigator. We must have a robust faith and yet not believe.

True science teaches us to doubt and, in ignorance, to refrain.

Beyond that, theory and concepts go to constitute a language in which the scientistic matters at issue can be formulated and discussed.

If Congress can determine what constitutes the general welfare and can appropriate money for its advancement, where is the limitation to carrying into execution whatever can be effected by money?.

An assumption cannot be used to justify making second-class citizens of those who are unfortunate enough to constitute living proof of the inaccuracy of that assumption.

Whenever he looked he saw the labour of existence; and this labour, recognised as such, was what constituted reality for him. (On Vincent Van Gogh)

History always constitutes the relation between a present and its past. Consequently fear of the present leads to mystification of the past

Sympathy constitutes friendship; but in love there is a sort of antipathy, or opposing passion. Each strives to be the other, and both together make up one whole.

As it must not, so genius cannot be lawless; for it is even that constitutes its genius – the power of acting creatively under laws of its own origination.

Be not merely a man of letters! Let literature be an honorable augmentations to your arms, not constitute the coat or fill the escutcheon!