Our greatest weakness lies in giving up.

To those searching for truth -- not the truth of dogma and darkness but the truth brought by reason, search, examination, and inquiry, discipline is required. 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 first requisite for success is to develop the ability to focus.

The real measure of success is the number of experiments that can be crowded into 24 hours.

The doctor of the future will give no medicine, but will involve the patient in the proper use of food, fresh air and exercise

Sleep is like a drug. Take too much at a time and it makes you dopey. You lose time and opportunities.

Incurably religious, that is the best way to describe the mental condition of so many people.