Ideas must work through the brains and the arms of good and brave men or they are no better than dreams.

If we live truly, we shall see truly. It is as easy for the strong man to be strong, as it is for the weak to be weak.

There comes a time in each man's education in which he comes to the conclusion that envy is ignorance, imitation is suicide, and society in in conspiracy against each one of its members.

No hope so bright but is the beginning of its own fulfilment.

For everything you gain, you lose something.

No one can read the history of astronomy without perceiving that Copernicus, Newton, Laplace, are not new men, or a new kind of men, but that Thales, Anaximenes, Hipparchus, Empodocles, Aristorchus, Pythagorus, Oenipodes, had anticipated them.

Many times the reading of a book has made the future of a man.