Louis Pasteur Quotes

I am on the edge of mysteries and the veil is getting thinner and thinner.

Letter, 1851


In the fields of observation, chance only favours the mind which is prepared.

Presentation to the Faculty of Sciences at Lille, 1854


There is a time in every man’s life when he looks to his God, when he looks at his life, when he wonders how he will be remembered.

Reflections on My Life by Louis Pasteur


When one works and imagines and dreams of nothing else than the search for answers that God has posed, it is difficult to be so still.

Revue Scientifique, 1871


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

Reflections on My Life by Louis Pasteur


The longer I live, the better I understand the kindness of thy heart and the high quality of thy mind.

Dedication to his father in the Preface of Physiological Theory of Fermentation, 1879


To bring one’s self to believe in a truth that has just dawned upon one is the first step towards progress; to persuade others is the second.

Physiological Theory of Fermentation, 1879


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.

Open Letter to Robert Koch, 1882


You have not succeeded in your experiments, that is all there is to it.

Open Letter to Robert Koch, 1882


You, my dear father, whose life was as hard as your trade, you showed me what patience can accomplish in prolonged efforts. To you I owe my tenacity in daily work.

Speech in Dôle, July 14, 1883