Our responsibility is to do what we can, learn what we can, improve the solutions, and pass them on.

Observation, reason, and experiment make up what we call the scientific method.

The basis of action on love, the brotherhood of all men, the value of the individual... the humility of the spirit.

A scientist is never certain. ... We absolutely must leave room for doubt or there is no progress and there is no learning.

But there is nothing in biology yet found that indicates the inevitability of death.

Listen, I mean that from my knowledge of the world that I see around me, I think that it is much more likely that the reports of flying saucers are the results of the known irrational characteristics of terrestrial intelligence than of the unknown rational efforts of extra-terrestrial intelligence.

'Conservation' (the conservation law) means this ... that there is a number, which you can calculate, at one moment-and as nature undergoes its multitude of changes, this number doesn't change. That is, if you calculate again, this quantity, it'll be the same as it was before. An example is the conservation of energy: there's a quantity that you can calculate according to a certain rule, and it comes out the same answer after, no matter what happens, happens.