There is nothing more difficult to carry out, nor more doubtful of success, nor more dangerous to handle, that to institute a new order of things

Our greatest glory is not in never failing, but in rising up every time we fail.

What one has to do usually can be done.

Results! Why, man, I have gotten a lot of results. I know several thousand things that won't work.

Success is going from failure to failure without loss of enthusiasm.

There is one weakness in people for which there is no remedy. It is the universal weakness of lack of ambition.

By failing to prepare, you are preparing to fail.

One must be sane to think clearly, but one can think deeply and be quite insane.

Don't spend time beating on a wall, hoping to transform it into a door.

If you think your teacher is tough, wait until you get a boss. He doesn't have tenure.

Success comes to those who become success conscious. Failure comes to those who indifferently allow themselves to become failure conscious.

Work does not kill a man, it is worry, irregularity and uncertainty that kill.

A person who never made a mistake never tried anything new.

In every job that must be done, there is an element of fun. You find the fun and - SNAP - the job's a game!

Of all the things I've done, the most vital is coordinating those who work with me and aiming their efforts at a certain goal

To invent, you need a good imagination and a pile of junk.

We struggle with the complexities and avoid the simplicities.

One of the main weaknesses of mankind is the average man's familiarity with the word 'impossible'.

I do know that when I am 60, I should be attempting to achieve different personal goals than those which had priority at age 20.

Change yourself and your work will seem different.

Old Professors never die, they just lose their faculties.