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.

Happy contractedness of youth, nay, of mankind in general, that they think neither of the high nor the deep, of the true nor the false, but only of what is suited to their own conceptions.

The whole history of the Christian Church is a mixture of errors and violence.

As soon as you are in a social setting, you better take away the key to the lock of your heart and pocket it; those who leave thekey in the lock are fools.

Don't dissipate your powers; strive to concentrate them. Genius thinks it can do whatever it sees others doing, but it will surely repent of every ill-judged outlay.

The senses do not deceive us, but the judgment does.

When the boy begins to understand that the visible point is preceded by an invisible point, that the shortest distance between two points is conceived as a straight line before it is ever drawn with pencil and paper...the fountain of all thought has been opened to him...the philosopher can reveal him nothing new, as a geometrician he has discovered the basis of all thought.