Intelligence is an extremely subtle concept. It's a kind of understanding that flourishes if it's combined with a good memory, but exists anyway even in the absence of good memory. It's the ability to draw consequences from causes, to make correct inferences, to foresee what might be the result, to work out logical problems, to be reasonable, rational, to have the ability to understand the solution from perhaps insufficient information. You know when a person is intelligent, but you can be easily fooled if you are not yourself intelligent.
Isaac AsimovOne would suppose that the battle for religious liberty was won in the United States two hundred years ago. However, in the time since, and right now, powerful voices are always raised in favor of bigotry and thought control. It is useful, then, to have a compendium of the thoughts of great men and women of all faiths (and of none) on the subject, to convince us that we men and woman of freedom are not and never have been alone.
Isaac AsimovThe Three Theorems of Psychohistorical Quantitivity: The population under scrutiny is oblivious to the existence of the science of Psychohistory. The time periods dealt with are in the region of 3 generations. The population must be in the billions (±75 billions) for a statistical probability to have a psychohistorical validity.
Isaac Asimov