Where the spirit does not work with the hand, there is no art.

If you find from your own experience that something is a fact and it contradicts what some authority has written down, then you must abandon the authority and base your reasoning on your own findings.

Feathers shall raise men even as they do birds towards heaven :- That is by letters written with their quills.

The acquisition of knowledge is always of use to the intellect, because it may thus drive out useless things and retain the good. For nothing can be loved or hated unless it is first known.

I have been impressed with the urgency of doing.

Every now and then go away, have a little relaxation, for when you come back to your work your judgment will be surer.

There are many occasions when the muscles that form the lips of the mouth move the lateral muscles that are joined to them, and there are an equal number of occasions when these lateral muscles move the lips of this mouth, replacing it where it cannot return of itself, because the function of muscle is to pull and not to push except in the case of the genitals and the tongue.