You see, there is no more purpose or meaning in the world than you put into it.

If error is corrected whenever it is recognized as such, the path of error is the path of truth.

It appears that the solution of the problem of time and space is reserved to philosophers who, like Leibniz, are mathematicians, or to mathematicians who, like Einstein, are philosophers.

Philosophy is regarded by many as inseparable from speculation. ... Philosophy has proceeded from speculation to science.

We must... maintain that mathematical geometry is not a science of space insofar as we understand by space a visual structure that can be filled with objects - it is a pure theory of manifolds.

Visual forms are not perceived differently from colors or brightness. They are sense qualities, and the visual character of geometry consists in these sense qualities.

Occasionally one speaks... of signals or signal chains. It should be noted that the word signal means the transmission of signs and hence concerns the very principle of causal order.

...the mathematician uses an indirect definition of congruence, making use of the fact that the axiom of parallels together with an additional condition can replace the definition of congruence.

Books can be dangerous. The best ones should be labeled ‘This could change your life’.

We live by faith and not by sight.

The best government is a benevolent tyranny tempered by an occasional assassination.

I wished for nothing beyond her smile, and to walk with her thus, hand in hand, along a sun warmed, flower bordered path.

People weren't meaning to be racist, but they didn't know. Action signals change, not intent. So when someone feels like they're not getting a fair shake, you gotta speak on it.

I can’t tell you just how wonderful she is. I don’t want you to know. I don’t want any one to know.

Think lovingly, speak lovingly, act lovingly, and every need shall be supplied.

A thick stick in one's hand makes people respectful.

Change before you're forced to change.

An accident, a random change, in any delicate mechanism can hardly be expected to improve it. Poking a stick into the machinery of one's watch or one's radio set will seldom make it work better.