Claude Bernard


French Physiologist

Author Quotes

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..

Indeed, proof that a given condition always precedes or accompanies a phenomenon does not warrant concluding with certainty that a given condition is the immediate cause of that phenomenon. It must still be established that when this condition is removed, the phenomen will no longer appear.

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.

Science does not permit exceptions.

The first entirely vital action, so termed because it is not effected outside the influence of life, consists in the creation of the glycogenic material in the living hepatic tissue. The second entirely chemical action, which can be effected outside the influence of life, consists in the transformation of the glycogenic material into sugar by means of a ferment.

The terrain is everything; the germ is nothing.

Two things are necessary - science and art, reason and emotion.

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.

I have been told that I find what I am not looking for, while Helmholtz finds only what he looks for. It is true, but the second direction is bad if it is exclusive.

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.

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.

Science increases our understanding in proportion as it lowers our pride.

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

The true worth of a researcher lies in pursuing what he did not seek in his experiment as well as what he sought.

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

Ideas develop spontaneously in the mind. and when one yields to his thoughts, he is like a man at the window watching the passers by....this requires no effort, and it even has great charm. Where the work is, and the fatigue, is to collar the idea, like one stops the passerby, despite his desire to flee; to retain it, to fix it and give it its character.

It is generally agreed that synthesis re-unites what analysis has divided, and that synthesis therefore verifies analysis, of which it is merely the counterproof or necessary complement.

Observation is a passive science, experimentation is an active science.

Science proceeds by revolution, and not by addition, pure and simple. This holds for theories, which are always successive.

The general or mineral world is made for all beings, and in turn each being has below him beings which are made for him, but does he have the feeling that he has something above him, for which he is made?

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.

We can learn nothing except by going from the known to the unknown.

A modern poet has characterized the personality of art and the impersonality of science as follows: Art is I: Science is We.

Even mistaken hypotheses and theories are of use in leading to discoveries. This remark is true in all the sciences. The alchemists founded chemistry by pursuing chimerical problems and theories which are false. In physical science, which is more advanced than biology, we might still cite men of science who make great discoveries by relying on false theories. It seems, indeed, a necessary weakness of our mind to be able to reach truth only across a multitude of errors and obstacles.

A physician?s subject of study is necessarily the patient, and his first field for observation is the hospital. But if clinical observation teaches him to know the form and course of diseases, it cannot suffice to make him understand their nature; to this end he must penetrate into the body to find which of the internal parts are injured in their functions. That is why dissection of cadavers and microscopic study of diseases were soon added to clinical observation. But to-day these various methods no longer suffice; we must push investigation further and, in analyzing the elementary phenomena of organic bodies, must compare normal with abnormal states. We showed elsewhere how incapable is anatomy alone to take account of vital phenenoma, and we saw that we must add study of all physico-chemical conditions which contribute necessary elements to normal or pathological manifestations of life. This simple suggestion already makes us feel that the laboratory of a physiologist-physician must be the most complicated of all laboratories, because he has to experiment with phenomena of life which are the most complex of all natural phenomena.

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French Physiologist