The trouble with most people is that they quit before they start.

High thinking is inconsistent with a complicated material life based on high speed and imposed on us by mammon worship.

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

The best thinking has been done in solitude. The worst has been done in turmoil.

There is no limit to which a man will not go to avoid thinking.

Even people who aren't geniuses can outthink the rest of mankind if they develop certain thinking habits.