The first precept was never to accept a thing as true until I knew it as such without a single doubt.

Divide each difficulty into as many parts as is feasible and necessary to resolve it.

Science is practical philosophy.

Perfect numbers like perfect men are very rare.

For each of us there is a set limit to our intellectual powers which we cannot pass.

Each problem that I solved became a rule, which served afterwards to solve other problems.

It is contrary to reasoning to say that there is a vacuum or space in which there is absolutely nothing.