Everything is theoretically impossible, until it is done. One could write a history of science in reverse by assembling the solemn pronouncements of … - Robert A. Heinlein

Everything is theoretically impossible, until it is done.

“Funny sort of science! I guess they were pretty ignorant in those days.”
“Don’t go running down our grandfathers. If it weren’t for them, you and I would be squatting in a cave, scratching fleas. No, Bub, they were pretty sharp; they just didn’t have all the facts. We’ve got more facts, but that doesn’t make us smarter.”

Man has no moral instinct. He is not born with moral sense. You were not born with it, I was not - and a puppy has none. We acquire moral sense, when we do, through training, experience, and hard sweat of the mind.

“Harry, I need advice.”
“You do? Well, I’ve got it in all sizes. All of it free and all of it worth what it costs, I’m afraid.”