Seek not proud riches, but such as thou mayest get justly, use soberly, distribute cheerfully, and leave contentedly.

If a man's wit be wandering, let him study the mathematics; for in demonstrations, if his wit be called away never so little, he must begin again.

The lame man who keeps the right road outstrips the runner who takes the wrong one.

There is another ground of hope that must not be omitted. Let men but think over their infinite expenditure of understanding, time, and means on matters and pursuits of far less use and value; whereof, if but a small part were directed to sound and solid studies, there is no difficulty that might not be overcome.

For whatever deserves to exist deserves also to be known, for knowledge is the image of existence, and things mean and splendid exist alike.

The first question concerning the Celestial Bodies is whether there be a system, that is whether the world or universe compose together one globe, with a center, or whether the particular globes of earth and stars be scattered dispersedly, each on its own roots, without any system or common center.

The joys of parents are secret, and so are their grieves and fears.