The greatest minds, as they are capable of the highest excellencies, are open likewise to the greatest aberrations; and those who travel very slowly may yet make far greater progress, provided they keep always to the straight road, than those who, while they run, forsake it.
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.
The last rule was to make enumerations so complete, and reviews so comprehensive, that I should be certain of omitting nothing.
Each problem that I solved became a rule, which served afterwards to solve other problems.