It is a test of true theories not only to account for but to predict phenomena.
I do not believe in conspiracy theories.
Theories are patterns without value. What counts is action.
I have no useful theories about love and marriage.
Theories pass. The frog remains.
I know my theories and findings are hard for you to accept because they are so original and extraordinary.
Theories are always very thin and insubstantial, experience only is tangible.
Theories that go counter to the facts of human nature are foredoomed.
Goals and objectives are based on theories and foundations.
People love conspiracy theories.