Claude Bernard


French Physiologist

Author Quotes

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

There are some doctors who declare themselves against experimentation, and only favour observation. This is erroneous thinking, for experimentation cannot exist without observation. Experiment is only provoked observation, carried further with the aid of instruments and other means of investigation - but basically still observation.

We must not deceive ourselves: morals do not forbid making experiments on one's neighbour or one's self; in everyday life, men do nothing but experiment on one another.

Experimental medicine is not a new system of medicine, but on the contrary, is the negation of all systems. A science that halted in a system would remain stationary and would be isolated, because systematization is really scientific encysting, and every encysted part of an organism ceases to take part in that organism's general life.

In experimentation, it is always necessary to start from a particular fact and proceed to the generalization....but above all, one must observe. (+)

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

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.

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.

The life of an organism can only continue through the birth of primitive or embryonic cells which mature little by little and then die at a given moment. As it is in organisms, so it is with people. Civilization is essentially a progression towards death. The upper classes do not lose their status. It is necessary that primitive, even barbaric men become civilized and ascend to join them. If this renewal fails to occur, society dies, as would an organism deprived of cellular renewal.

There are those who believe that criticism consists in attaching oneself to a man, and taking away from him all that he has been able to do of value.

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.

Experimentation is an active science.

In science the important thing is to modify and change one's ideas as science advances.

It's what we think we know that keeps us from learning.

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

The constancy of the internal environment is the condition for free and independent life: the mechanism that makes it possible is that which assured the maintenance, with the internal environment, of all the conditions necessary for the life of the elements.

The man of genius is an absurd person, who pushes reasoning to the limit and makes a system. I could be a man of genius, but I do not wish to be: I prefer to be a reasonable man.

They make poor observations, because they choose among the results of their experiments only what suits their object, neglecting whatever is unrelated to it and carefully setting aside everything which might tend toward the idea they wish to combat.

We see, then, that the elements of the scientific method are interrelated. Facts are necessary materials; but their working up by experimental reasoning, i.e., by theory, is what establishes and really builds up science. Ideas, given form by facts, embody science. A scientific hypothesis is merely a scientific idea, preconceived or previsioned. A theory is merely a scientific idea controlled by experiment. Reasoning merely gives a form to our ideas, so that everything, first and last, leads back to an idea. The idea is what establishes, as we shall see, the starting point or the primum movens of all scientific reasoning, and it is also the goal in the mind's aspiration toward the unknown.

False scientists have a great thirst to explain everything, but are not very ardent for proof. They explain everything but never prove anything. They hasten to explain, but not to prove.

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

Laplace considers astronomy a science of observation, because we can only observe the movements of the planets; we cannot reach them, indeed, to alter their course and to experiment with them. On earth, said Laplace, we make phenomena vary by experiments; in the sky, we carefully define all the phenomena presented to us by celestial motion. Certain physicians call medicine a science of observations, because they wrongly think that experimentation is inapplicable to it.

Philosophy concerns itself with the beginning and the end of things. It is those extremes which challenge us. Science does not concern itself with either the beginning or the end: it deals with the present.

The defects of the day: no respect for authority; devaluation of all existing reputations. It is the pride of youth and the contempt for the fathers, for the ancients in all the sciences. This is a bad spirit, because we are often only dwarfs standing on their shoulders. They should without doubt not be worshipped, but be known and appreciated.

The mental never influences the physical. It is always the physical that modifies the mental, and when we think that the mind is diseased, it is always an illusion.

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French Physiologist