“No great discovery was ever made without a bold guess.”

Poetry is a kind of ingenious nonsense.

A body in motion tends to stay in motion unless acted on by an outside force.

I see I have made my self a slave to philosophy.

You have to make the rules, not follow them.

Tact is the art of making a point without making an enemy.

Where both are friends, it is right to prefer truth.

Opposite to godliness is atheism in profession, and idolatry in practice. Atheism is so senseless and odious to mankind, that it never had many professors.

Let me think – I wonder if an anvil will drop like an apple?

If the experiments which I urge be defective, it cannot be difficult to show the defects; but if valid, then by proving the theory, they must render all objections invalid.

When two forces unite, their efficiency double.

The best way to understanding is a few good examples.

The great ocean of truth lay all undiscovered before me.

The centre of the system of the world is immovable.

All knowledge and understanding of the Universe was no more than playing with stones and shells on the seashore of the vast imponderable ocean of truth.

Every body persists in a state of rest or of uniform motion in a straight line, unless it is compelled to change that state by forces having impact upon it.

An object that is at rest will tend to stay at rest. An object that is in motion will tend to stay in motion.