If we are to achieve things never before accomplished we must employ methods never before attempted

Observation and experiment for gathering material, induction and deduction for elaborating it: these are are only good intellectual tools.

Doctor Johnson said, that in sickness there were three things that were material; the physician, the disease, and the patient: and if any two of these joined, then they get the victory; for, Ne Hercules quidem contra duos [Not even Hercules himself is a match for two]. If the physician and the patient join, then down goes the disease; for then the patient recovers: if the physician and the disease join, that is a strong disease; and the physician mistaking the cure, then down goes the patient: if the patient and the disease join, then down goes the physician; for he is discredited.

For my name and memory I leave to men's charitable speeches, and to foreign nations and the next ages.

It is a strange desire, to seek power, and to lose liberty; or to seek power over others, and to lose power over a man's self.

Images also help me find and realise ideas. I look at hundreds of very different, contrasting images and I pinch details from them, rather like people who eat from other people`s plates.

The universe must not be narrowed down to the limit of our understanding, but our understanding must be stretched and enlarged to take in the image of the universe as it is discovered.