Where evil habits are once settled, they are more easily broken than mended.

In almost everything, experience is more valuable than precept.

Nothing is more dangerous to men than a sudden change of fortune.

The prosperous can not easily form a right idea of misery.

Consequently the student who is devoid of talent will derive no more profit from this work than barren soil from a treatise on agriculture.

While we are examining into everything we sometimes find truth where we least expected it.