Perseverance is the most overrated of traits, if it is unaccompanied by talent; beating your head against a wall is more likely to produce a concussion in the head than a hole in the wall.

Isolation always perverts; when a man lives only among his own sort, he soon begins to believe that his sort are the best sort. This attitude breeds both the arrogance of the conservative and the bitterness of the radical.

The pessimist sees only the tunnel; the optimist sees the light at the end of the tunnel; the realist sees the tunnel and the light - and the next tunnel.

The deepest and rarest kind of courage has nothing to do with feats or obstacles in the outside world; and, indeed, has nothing to do with the outside world - it is the courage to be who you are.

A loser says that's the way it's always been done. A winner says there ought to be a better way.

Self-discipline without talent can often achieve astounding results, whereas talent without self-discipline inevitably dooms itself to failure.

It may be true that the weak will always be driven to the wall; but it is the task of a just society to see that the wall is climbable.