Ifs Quote by Mao Zedong

Theory is good; but it doesn't prevent things from existing.

— Jean-Martin Charcot

Theory, from whatever source, is not perfect until it is reduced to practice.

— Hosea Ballou

If the theory accurately predicts what they [scientists] see, it confirms that it's a good theory. If they see something that the theory didn't…

— Clayton Christensen

It really is a nice theory. The only defect I think it has is probably common to all philosophical theories. It's wrong.

— Anonymous

“Do not be afraid of the word 'theory'. Yes, it can sound dauntingly abstract at times, and in the hands of some writers can…

— Richard Howells

No particular theory may ever be regarded as absolutely certain.... No scientific theory is sacrosanct...

— Karl Popper

Theory is worth but little, unless it can explain its own phenomena, and it must effect this without contradicting itself; therefore, the facts are…

— Charles Caleb Colton

A theory is a good theory if it satisfies two requirements: it must accurately describe a large class of observations on the basis of…

— Stephen Hawking

There is nothing so practical as a good theory.

— Kurt Lewin

Some theories are good for nothing except to be argued about.

— Georg C. Lichtenberg

Any theory is better than no theory.

— Fuller Albright

I never read theory. I think that was to my benefit.

— Nan Goldin