Whoever in debate quotes authority uses not intellect, but memory.
The sun gives spirit and life to the plants and the earth nourishes them with moisture.
Nothing can be loved or hated unless it is first known.
Many will think they may reasonably blame me by alleging that my proofs are opposed to the authority of certain men held in the highest reverence by their inexperienced judgments; not considering that my works are the issue of pure and simple experience.
Depth and strength of a human character are defined by its moral reserves.
Avoid the precepts of those thinkers whose reasoning is not confirmed by experience.