Claude Bernard Quotes

It is what we know already that often prevents us from learning.

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

The terrain is everything; the germ is nothing.

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.

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.

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

Man can learn nothing unless he proceeds from the known to the unknown.

Mediocre men often have the most acquired knowledge

The minds that rise and become really great are never self-satisfied, but still continue to strive.

Those who do not know the torment of the unknown cannot have the joy of discovery.

All the vital mechanisms, varied as they are, have only one object, that of preserving constant the conditions of life in the internal environment.

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.

Feeling alone guides the mind.

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

Science does not permit exceptions.

Art is 'I'; science is 'we'.

A fact in itself is nothing. It is valuable only for the idea attached to it, or for the proof which it furnishes.

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

It has often been said that, to make discoveries, one must be ignorant. This opinion, mistaken in itself, nevertheless conceals a truth. It means that it is better to know nothing than to keep in mind fixed ideas based on theories whose confirmation we constantly seek, neglecting meanwhile everything that fails to agree with them.

Progress is achieved by exchanging our theories for new ones which go further than the old, until we find one based on a larger number of facts. ... Theories are only hypotheses, verified by more or less numerous facts. Those verified by the most facts are the best, but even then they are never final, never to be absolutely believed.

Descriptive anatomy is to physiology what geography is to history, and just as it is not enough to know the typography of a country to understand its history, so also it is not enough to know the anatomy of organs to understand their functions.

The joy of discovery is certainly the liveliest that the mind of man can ever feel.

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.

We must alter theory to adapt it to nature, but not nature to adapt it to theory.‎

Particular facts are never scientific; only generalization can establish science.