Should I not be proud, when for twenty years I have had to admit to myself that the great Newton and all the mathematicians and noble calculators along with him were involved in a decisive error with respect to the doctrine of color, and that I among millions was the only one who knew what was right in this great subject of nature?

Girls we love for what they are; young men for what they promise to be.

There is nothing by which men display their character so much as in what they consider ridiculous... Fools and sensible men are equally innocuous. It is in the half fools and the half wise that the great danger lies.

Time is a strange thing. It is a whimsical tyrant, which in every century has a different face for all that one says and does.

Beware of dissipating your powers; strive constantly to concentrate them.

Life is the childhood of our immortality.

Love grants in a moment what toil can hardly acheive in an age.