If you spend too much time thinking about a thing, you'll never get it done.

If you think a thing is impossible, you'll make it impossible.

I cannot teach anybody anything, I can only make them think.

To study and not think is a waste. To think and not study is dangerous.

Reading, after a certain age, diverts the mind too much from its creative pursuits. Any man who reads too much and uses his own brain too little falls into lazy habits of thinking.

The whole of science is nothing more than a refinement of everyday thinking.

A public-opinion poll is no substitute for thought.

If everybody is thinking alike, then somebody isn't thinking.

He who thinks little, errs much.

Don't think about what you've left behind.

"Why do you need to think? Can't we just sit and go budumbudumbudum with our lips for a bit?"

Thinking is the hardest work there is, which is probably the reason why so few engage in it.

To know what people really think, pay regard to what they do, rather than what they say.

The universe is a lot more complicated than you might think even if you start from a position of thinking that its pretty damn complicated to begin with.

Character is higher than intellect...A great soul will be strong to live, as well as strong to think.