Quotes by Louis Pasteur

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

Do not put forward anything that you cannot prove by experimentation.

Time is the best appraiser of scientific work, and I am aware that an industrial discovery rarely produces all its fruit in the hands of its first inventor.

The Ancients understood the omnipotence of the underside of things.

It would seem to me that I was committing a theft if I were to let one day go by without doing some work.

Science and Peace will triumph over Ignorance and War.

My strength lies solely in my tenacity.

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. Sédillot) to the method of cultivation out of the body.

The grandeur of the acts of men are measured by the inspiration from which they spring.

As in the experimental sciences, truth cannot be distinguished from error as long as firm principles have not been established through the rigorous observation of facts.

We affirm the neutrality of Science ... Science is of no country. ... But if Science has no country, the scientist must keep in mind all that may work towards the glory of his country. In every great scientist will be found a great patriot.

Change only favours minds that are diligently looking and preparing for discovery.

Herrmann Pidoux and Armand Trousseau stated 'Disease exists within us, because of us, and through us', Pasteur did not entirely disagree, 'This is true for certain diseases', he wrote cautiously, only to add immediately: 'I do not think that it is true for all of them'.

It is a matter of fact; I approached without a preconceived idea, too ready to declare, if the experiment had imposed upon me the confession, that there was a spontaneous generation, of
which I am convinced today that those who assure it are blindfolded.

If perchance you should falter during the journey, a hand would be there to support you. If that should be wanting, God, who alone could take that hand from you, would Himself accomplish its work.

The greatest malfunction of spirit is to believe things.

These three things -- work, will, success -- fill human existences. Will opens the door to success, both brilliant and happy. Work passes these doors, and at the end of the journey success comes in to crown one's efforts.

The more I know, the more nearly is my faith that of the Breton peasant. Could I but know all I would have the faith of a Breton peasant woman.

Since the most ancient times, all men, and particularly those who endeavored in the practice of medicine, have brought closer together two natural phenomena of capital importance: illness or fever and fermentation.

Science advances through tentative answers to a series of more and more subtle questions which reach deeper and deeper into the essence of natural phenomena.

If you suppress laboratories, physical science will be stricken with barrenness and death.

The nights seem to me too long... I am often scolded by Madame Pasteur, but I tell her I shall lead her to fame.

Whatever your career may be, do not let yourselves become tainted by a deprecating and barren scepticism.

After death, life reappears in a different form and with different laws. It is inscribed in the laws of the permanence of life on the surface of the earth and everything that has been a plant and an animal will be destroyed and transformed into a gaseous, volatile and mineral substance.

Bernard was right. The germ is nothing, the terrain is everything.

The flavor of wine is like delicate poetry.

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

The Greeks bequeathed to us one of the most beautiful words in our language -- the word 'enthusiasm' -- en theos -- a god within. The grandeur of human actions is measured by the inspiration from which they spring. Happy is he who bears a god within, and who obeys it.

Let me tell you the secret that has led me to my goal: my strength lies solely in my tenacity.

When I approach a child, he inspires in me two sentiments -- tenderness for what he is and respect for what he may become.

Chance favors the prepared mind.

Never will the doctrine of spontaneous generation recover from the mortal blow struck by this simple experiment.

It is surmounting difficulties that makes heroes.

There are no such things as applied sciences, only applications of science.

Science knows no country, because knowledge belongs to humanity, and is the torch which illuminates the world.

The universe is asymmetric and I am persuaded that life, as it is known to us, is a direct result of the asymmetry of the universe or of its indirect consequences.

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.