Science is a wonderful thing if one does not have to earn one's living at it. One should earn one's living by work of which one is sure one is capable. Only when we do not have to be accountable to anybody can we find joy in scientific endeavor.

About Newton: Nature to him was an open book, whose letters he could read without effort.

"There's been a quantum leap technologically in our age, but unless there's another quantum leap in human relations, unless we learn to live in a new way towards one another, there will be a catastrophe."

In their struggle for the ethical good, teachers of religion must have the stature to give up the doctrine of a personal god, that is, give up that source of fear and hope which in the past placed such vast power in the hands of priests. In their labors they will have to avail themselves of those forces which are capable of cultivating the Good, the True, and the Beautiful in humanity itself. This is, to be sure, a more difficult but an incomparably more worthy task.

There are few enough people with sufficient independence to see the weaknesses and follies of their contemporaries and remain themselves untouched by them.

Give back to the world at least what you've received.

However we select from nature a complex [of phenomena] using the criterion of simplicity, in no case will its theoretical treatment turn out to be forever appropriate (sufficient).... I do not doubt that the day will come when [general relativity], too, will have to yield to another one, for reasons which at present we do not yet surmise. I believe that this process of deepening theory has no limits.