It doesn’t matter how beautiful your theory is, it doesn’t matter how smart you are. If it doesn’t agree with experiment, it’s wrong. Richard Feynman
You can’t run a business or anything else on a theory. Harold Geneen
Facts do not ‘speak for themselves’, they are read in the light of theory. Stephen Jay Gould
The great tragedy of science, the slaying of a beautiful theory by an ugly fact. T H Huxley
Life is so unlike theory. Anthony Trollope
Theory can leave questions unanswered, but practice has to come up with something. Mason Cooley
A theory if you hold it hard enough
And long enough gets rated as a creed….
Robert Frost
Whenever a theory appears to you as the only possible one, take this as a sign that you have neither understood the theory nor the problem which it was intended to solve. Karl Popper
It’s a huge mistake to theorize before one has the facts because you begin to twist the facts to match the theory. Ron Woods
Don’t confuse hypothesis and theory. The former is a possible explanation; the latter, the correct one. The establishment of theory is the very purpose of science. Martin H Fischer
The moment a person forms a theory, his imagination sees in every object only the traits which favour that theory. Thomas Jefferson