Ask yourself whether our language is complete--whether it was so before the symbolism of chemistry and the notation of the infinitesimal calculus were incorporated in it; for these are, so to speak, suburbs of our language. (And how many houses or streets does it take before a town begins to be a town?) Our language can be seen as an ancient city: a maze of little streets and squares, of old and new houses, and of houses with additions from various periods; and this surrounded by a multitude of new boroughs with straight regular streets and uniform houses.

The popular scientific books by our scientists aren't the outcome of hard work, but are written when they are resting on their laurels.

There can never be surprises in logic.

An honest religious thinker is like a tightrope walker. He almost looks as though he were walking on nothing but air. His support is the slenderest imaginable. And yet it really is possible to walk on it.

Black seems to make a colour cloudy, but darkness doesn't. A ruby could thus keep getting darker without ever becoming cloudy; but if it became blackish red, it would become cloudy.

A propositional sign, applied and thought out, is a thought. A thought is a proposition with a sense.

A confession has to be part of your new life.