But by far the greatest obstacle to the progress of science and to the undertaking of new tasks and provinces therein is found in this - that men despair and think things impossible.

It is not possible to run a course aright when the goal itself has not been rightly placed.

Those who have handled sciences have been either men of experiment or men of dogmas. The men of experiment are like the ant, they only collect and use; the rea…

But the best demonstration by far is experience, if it go not beyond the actual experiment.

It's a great game to look at the past, at an unscientific era, look at something there, and say have we got the same thing now, and where is it? So I would lik…

Let us be honest. Did all the priests of Rome increase the mental wealth of man as much as Bruno? Did all the priests of France do as great a work for the civi…

You can hardly convince a man of an error in a lifetime, but must content yourself with the reflection that the progress of science is slow. If he is not convi…