Louis Pasteur


French Chemist and Microbiologist who created the first vaccine for Rabies and Anthrax

Author Quotes

I beseech you to take interest in these sacred domains so expressively called laboratories. Ask that there be more and that they be adorned for these are the temples of the future, wealth and well-being. It is here that humanity will grow, strengthen and improve. Here, humanity will learn to read progress and individual harmony in the works of nature, while humanity's own works are all too often those of barbarism, fanaticism and destruction.

Science is the highest personification of the nation because that nation will remain the first which carries the furthest the works of thought and intelligence.

You delegates of foreign countries who have come a long way to show your sympathy for France, have given me the greatest joy a man can feel who believes that Science and Peace will prevail over Ignorance and War, that the nations will learn to understand each other, not for destruction but for advancement, and that the future belongs to those who have done most for suffering mankind. Young men? Ask yourselves first: What have I done for my education? And as you gradually advance: What have I done for my country? ? Until the moment comes when you experience the tremendous gratification of knowing that in some measure you have contributed to the progress and welfare of mankind. More or less favored by the current of life as your efforts may be, you must have the right to say, on approaching the great goal: I have done all I could do.

I give them experiments and they respond with speeches.

Science knows no country because it is the light that illuminates the world.

I propose to provide proof... that just as always an alcoholic ferment, the yeast of beer, is found where sugar is converted into alcohol and carbonic acid, so always a special ferment, a lactic yeast, is found where sugar is transformed into lactic acid. And, furthermore, when any plastic nitrogenated substance is able to transform sugar into that acid, the reason is that it is a suitable nutrient for the growth of the [lactic] ferment.

The artificial products do not have any molecular dissymmetry; and I could not indicate the existence of a more profound separation between the products born under the influence of life and all the others.

If it is a terrifying thought that life is at the mercy of the multiplication of these minute bodies [microbes], it is a consoling hope that Science will not always remain powerless before such enemies...

The greatest derangement of the mind is to believe in something because one wishes it to be so.

A bottle of wine contains more philosophy than all the books in the world.

If science has no country, the scientist should have one, and ascribe to it the influence which his works may have in this world.

The greatest disorder of the mind is to let will direct it.

Acknowledging the role of molecules that have stereoisomers, some the mirror image of the others, and microorganisms whose chemistry prefers only one of those forms.

Imagination should give wings to our thoughts but we always need decisive experimental proof, and when the moment comes to draw conclusions and to interpret the gathered observations, imagination must be checked and documented by the factual results of the experiment.

There does not exist a category of science to which one can give the name applied science. There are science and the applications of science, bound together as the fruit of the tree which bears it.

Analogy cannot serve as proof.

Intuition is given only to him who has undergone long preparation to receive it.

There is no such thing as a special category of science called applied science; there is science and its applications, which are related to one another as the fruit is related to the tree that has borne it.

Are the atoms of the dextroacid (tartaric) grouped in the spirals of a right-hand helix or situated at the angles of an irregular tetrahedron, or arranged in such or such particular unsymmetrical fashion? We are unable to reply to these questions. But there can be no reason for doubting that the grouping of the atoms has an unsymmetrical arrangement with a non-superimposable image. It is not less certain that the atoms of the laevo-acid realize precisely an unsymmetrical arrangement of the inverse of the above.

It is surmounting difficulties that makes heroes.

These microscopic organisms form an entire world composed of species, families and varieties whose history, which has barely begun to be written, is already fertile in prospects and findings of the highest importance. The names of these organisms are very numerous and will have to be defined and in part discarded. The word microbe which has the advantage of being shorter and carrying a more general meaning, and of having been approved by my illustrious friend, M. Littr‚, the most competent linguist in France, is one we will adopt.

As I show you this liquid, I too could tell you, 'I took my drop of water from the immensity of creation, and I took it filled with that fecund jelly, that is, to use the language of science, full of the elements needed for the development of lower creatures. And then I waited, and I observed, and I asked questions of it, and I asked it to repeat the original act of creation for me; what a sight it would be! But it is silent! It has been silent for several years, ever since I began these experiments. Yes! And it is because I have kept away from it, and am keeping away from it to this moment, the only thing that it has not been given to man to produce, I have kept away from it the germs that are floating in the air, I have kept away from it life, for life is the germ, and the germ is life.'

Live in the serene peace of laboratories and libraries

To demonstrate experimentally that a microscopic organism actually is the cause of a disease and the agent of contagion, I know no other way, in the present state of Science, than to subject the microbe (the new and happy term introduced by M. S‚dillot) to the method of cultivation out of the body.

Bernard was right; the pathogen is nothing; the terrain is everything. [deathbed words]

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French Chemist and Microbiologist who created the first vaccine for Rabies and Anthrax