I never perfected an invention that I did not think about in terms of the service it might give others... I find out what the world needs, then I proceed to invent.

Nineteen hundred and three will bring great advances in surgery, in the study of bacteria, in the knowledge of the cause and prevention of disease. Medicine is played out. Every new discovery of bacteria shows us all the more convincingly that we have been wrong and that the million tons of stuff we have taken was all useless.

This problem, once solved, will be simple.

To do much clear thinking a person must arrange for regular periods of solitude when they can concentrate and indulge the imagination without distraction.

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.

From his neck down a man is worth a couple of dollars a day, from his neck up he is worth anything that his brain can produce.

I try not to invent things that people don't need.