Quote by Leslie Feinberg

“There is no theory that is not a fragment, carefully prepared, of some autobiography.”

— Paul Valery

“This is why theory can be so valuable: it can explain what will happen, even before you experience it.”

— Clayton M. Christensen

“In the past a theory could get by on its beauty; in the modern world a successful theory has to work for a living.”

— Howard Wainer

“You can't learn what you're unable to understand but a theory is infeasible until you won't need it.”

— Robin Sacredfire

“You can't learn what you can't understand but any theory is infeasible until you don't need it.”

— Robin Sacredfire

“Progress is proven through action, not theory.”

— Marion Bekoe

“If theory means a reasonably systematic reflection of our guiding assumptions, it remains as indispensable as ever.”

— Terry Eagleton

“That' the thing about theories. You can theorize all you want, but at the end of the day when you theories become reality, when…

— Jane Green

“A work in which there are theories is like an object which still has its price-tag on.”

— Marcel Proust

“Theories were clean and convincing and comprehensible. Life was messy and full of nonsense.”

— Julian Barnes

“Theory becomes realized among a people only in so far as it represents the realization of that people's needs.”

— Karl Marx

Action will remove the doubts that theory cannot solve.

— Tehyi Hsieh