No scientist thinks in formulae.

No idea is conceived in our mind independent of our five senses [i.e., no idea is divinely inspired].

For scientific endeavor is a natural whole the parts of which mutually support one another in a way which, to be sure, no one can anticipate.

My primary process of perceiving is muscular and visual.

The wonder of nature does not become smaller because one cannot measure it by the standards of human moral and human aims.

[Newton wrote to Halley ... that he would not give Hooke any credit] That, alas, is vanity. You find it in so many scientists. You know, it has always hurt me to think that Galileo did not acknowledge the work of Kepler.

Mere thinking cannot reveal to us the highest purpose.