It's the writing that teaches you.

The 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.

Meanwhile, fears of universal disaster sank to an all time low over the world.

Until now in world's history, whenever we've had a dark age, its been temporary and local. And other parts of the world have been doing fine. And eventually, they help you get out of the dark age. We are now facing a possible dark age which is going to be world-wide and permanent! That's not fun. That's a different thing. But once we have established many worlds, we can do whatever we want as long as we do it one world at a time.

It's humbling to think that all animals, including human beings, are parasites of the plant world.

The first law of dietetics seems to be: if it tastes good, it's bad for you.

Today's science fiction is tomorrow's science fact.