Claude Bernard Quotes

Hatred is the most clear- sighted, next to genius.

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.

The physiologist is not a man of the world, he is a scientist, a man caught and absorbed by a scientific idea that he pursues; he no longer hears the cries of the animals, no longer sees the flowing blood, he sees only his idea: organisms that hide from him problems that he wants to discover. He doesn't feel that he is in a horrible carnage; under the influence of a scientific idea, he pursues with delight a nervous filament inside stinking and livid flesh that for any other person would be an object of disgust and horror.

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.

A discovery is generally an unforeseen relation not included in theory.

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

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.

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

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

When entering on new ground we must not be afraid to express even risky ideas so as to stimulate research in all directions. As Priestley put it, we must not remain inactive through false modesty based on fear of being mistaken.

Man does not limit himself to seeing; he thinks and insists on learning the meaning of phenomena whose existence has been revealed to him by observation. So he reasons, compares facts, puts questions to them, and by the answers which he extracts, tests one by another. This sort of control, by means of reasoning and facts, is what constitutes experiment, properly speaking; and it is the only process that we have for teaching ourselves about the nature of things outside us.

In every enterprise ... the mind is always reasoning, and, even when we seem to act without a motive, an instinctive logic still directs the mind. Only we are not aware of it, because we begin by reasoning before we know or say that we are reasoning, just as we begin by speaking before we observe that we are speaking, and just as we begin by seeing and hearing before we know what we see or what we hear.

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.

Feeling alone guides the mind.

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

With the aid of these active experimental sciences man becomes an inventor of phenomena, a real foreman of creation; and under this head we cannot set limits to the power that he may gain over nature through future progress of the experimental sciences.

First causes are outside the realm of science.

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

The true worth of an experimenter consists in his pursuing not only what he seeks in his experiment, but also what he did not seek.

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

Real science exists, then, only from the moment when a phenomenon is accurately defined as to its nature and rigorously determined in relation to its material conditions, that is, when its law is known. Before that, we have only groping and empiricism.

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

[Those] who have an excessive faith in their theories or in their ideas are not only poorly disposed to make discoveries, but they also make very poor observations.

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.

Science does not permit exceptions.

Ardent desire for knowledge, in fact, is the one motive attracting and supporting investigators in their efforts; and just this knowledge, really grasped and yet always flying before them, becomes at once their sole torment and their sole happiness. Those who do not know the torment of the unknown cannot have the joy of discovery which is certainly the liveliest that the mind of man can ever feel.

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.

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.

Effects vary with the conditions which bring them to pass, but laws do not vary. Physiological and pathological states are ruled by the same forces; they differ only because of the special conditions under which the vital laws manifest themselves.

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

To be worthy of the name, an experimenter must be at once theorist and practitioner. While he must completely master the art of establishing experimental facts, which are the materials of science, he must also clearly understand the scientific principles which guide his reasoning through the varied experimental study of natural phenomena. We cannot separate these two things: head and hand. An able hand, without a head to direct it, is a blind tool; the head is powerless without its executive hand.