For faith, as well intentioned as it may be, must be built on facts, not fiction - faith in fiction is a damnable false hope.

The great trouble is that the preachers get the children from six to seven years of age and then it is almost impossible to do anything with them.

A failure teaches you that something can't be done-that way.

Until man duplicates a blade of grass, nature can laugh at his so called scientific knowledge.

I think work is the world's greatest fun.

Anything that won't sell, I don't want to invent. Its sale is proof of utility, and utility is success.

After we had conducted thousands of experiments on a certain project without solving the problem, one of my associates, after we had conducted the crowning experiment and it had proved a failure, expressed discouragement and disgust over our having failed to find out anything. I cheerily assured him that we had learned something. For we had learned for a certainty that the thing couldnt be done that way, and that we would have to try some other way.