A true proposition is a proposition belief which would never lead to such disappointment so long as the proposition is not understood otherwise than it was intended.

We should chiefly depend not upon that department of the soul which is most superficial and fallible (our reason), but upon that department that is deep and sure, which is instinct.

Another characteristic of mathematical thought is that it can have no success where it cannot generalize.

Bad reasoning as well as good reasoning is possible; and this fact is the foundation of the practical side of logic.

The opinion which is fated to be ultimately agreed to by all who investigate, is what we mean by the truth, and the object represented in this opinion is the real. That is the way I would explain reality.

It is not knowing, but the love of learning, that characterizes the scientific man.

We do not really think, we are barely conscious, until something goes wrong.