Walter Dill Scott quotes:

Mental attitude is more important than mental capacity.

Failure or success in business is primarily not determined by mental capacity but by MENTAL ATTITUDES

Success or failure in business is caused more by mental attitude even than by mental capacity. Banish the fear-attitude; acquire the confident attitude. And remember that the only way to acquire it is-to acquire it.

It is more than probable that the average man could, with no injury to his health, increase his efficiency fifty percent.