Lose the day loitering, 'twill be the same story To-morrow, and the next more dilatory, For indecision brings its own delays, And days are lost lamenting o'er lost days. Are you in earnest? Seize this very minute! What you can do, or think you can, begin it! Only engage, and then the mind grows heated; Begin it, and the work will be completed.

A useless life is an early death.

I could never have known so well how paltry men are, and how little they care for really high aims, if I had not tested them by my scientific researches. Thus I saw that most men only care for science so far as they get a living by it, and that they worship even error when it affords them a subsistence.

All professional men are handicapped by not being allowed to ignore things which are useless.

Our passions are true phoenixes; as the old burn out the new straight rise up from the ashes.

You are, when all is done-just what you are.

No one can take from us the joy of the first becoming aware of something, the so-called discovery. But if we also demand the honor, it can be utterly spoiled for us, for we are usually not the first. What does discovery mean, and who can say that he has discovered this or that? After all it's pure idiocy to brag about priority; for it's simply unconscious conceit, not to admit frankly that one is a plagiarist.