The world as we have created it is a process of our thinking. It cannot be changed without changing our thinking.

Whatever you think, that you will be. If you think yourselves weak, weak you will be; if you think yourselves strong, strong you will be.

Rarely do we find men who willingly engage in hard, solid thinking. There is an almost universal quest for easy answers and half-baked solutions. Nothing pains some people more than having to think.

All I have to do is think and not be influenced by other.

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

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