If I found any new truths in the sciences, I can say that they follow from, or depend on, five or six principal problems which I succeeded in solving and which I regard as so many battles where the fortunes of war were on my side.

We never understand a thing so well,and make it our own, as when we have discovered it for ourselves.

Every man is indeed bound to do what he can to promote the good of others, and a man who is of no use to anyone is strictly worthless.

Instead I ought to be grateful to Him who never owed me anything for having been so generous to me, rather than think that He deprived me of those things or has taken away from me whatever He did not give me.

Reason is nothing without imagination.

Good sense is the most equitably distributed of all things because no matter how much or little a person has, everyone feels so abundantly provided with good sense that he feels no desire for more than he already possesses.

If I found any new truths in the sciences, I can say that they follow from, or depend on, five or six principal problems which I succeeded in solving and which I regard as so many battles where the fortunes of war were on my side.