The only time you mustn't fail is the last time you try.

We have reason not to be afraid of the machine, for there is always constructive change, the enemy of machines, making them change to fit new conditions.

A problem well stated is a problem half-solved.

Every great improvement has come after repeated failures. Virtually nothing comes out right the first time. Failures, repeated failures, are finger posts on the road to achievement. One fails forward toward success.

The only time you mustn't fail is the last time you try.

Nothing ever built arose to touch the skies unless some man dreamed that it should, some man believed that it could, and some man willed that it must.

If I want to stop a research program I can always do it by getting a few experts to sit in on the subject, because they know right away that it was a fool thing to try in the first place.