A fake fortuneteller can be tolerated. But an authentic soothsayer should be shot on sight. Cassandra did not get half the kicking around she deserved.

A human being should be able to change a diaper, plan an invasion, butcher a hog, conn a ship, design a building, write a sonnet, balance accounts, build a wall, set a bone, comfort the dying, take orders, give orders, cooperate, act alone, solve equations, analyze a new problem, pitch manure, program a computer, cook a tasty meal, fight efficiently, die gallantly. Specialization is for insects.

A magician is a rule-of-thumb engineer. … And…a philosopher is a scientist with no thumbs.

A touchstone to determine the actual worth of an “intellectual”—find out how he feels about astrology.

A zygote is a gamete’s way of producing more gametes. This may be the purpose of the universe.

A “critic” is a man who creates nothing and thereby feels qualified to judge the work of creative men. There is logic in this; he is unbiased—he hates all creative people equally.

A “pacifist male” is a contradiction in terms. Most self-described “pacifists” are not pacific; they simply assume false colors. When the wind changes, they hoist the Jolly Roger.

Always listen to experts.They’ll tell you what can’t be done, and why. Then do it.

Always store beer in a dark place.

Any priest or shaman must be presumed guilty until proved innocent.

Anyone who cannot cope with mathematics is not fully human. At best he is a tolerable subhuman who has learned to wear shoes, bathe and not make messes in the house

But does Man have any “right” to spread through the universe? Man is what he is, a wild animal with the will to survive, and (so far) the ability, against all competition. Unless one accepts that, anything one says about morals, war, politics, you name it, is nonsense. Correct morals arise from knowing what man is, not what do-gooders and well-meaning old Aunt Nellies would like him to be. The Universe will let us know—later—whether or not Man has any “right” to expand through it.

By the data to date, there is only one animal in the Galaxy dangerous to man—man himself. So he must supply his own indispensable competition. He has no enemy to help him.

Certainly the game is rigged. Don’t let that stop you; if you don’t bet, you can’t win.

Cheops’ Law: Nothing ever gets built on schedule or within budget.

Delusions are often functional. A mother’s opinions about her children’s beauty, intelligence, goodness, et cetera ad nauseam, keep her from drowning them at birth.

Democracy can’t work. Mathematicians, peasants, and animals, that’s all there is—so democracy, a theory based on the assumption that mathematicians and peasants are equal, can never work.

Everything is theoretically impossible, until it is done. One could write a history of science in reverse by assembling the solemn pronouncements of highest authority about what could not be done and could never happen.

Expertise in one field does not carry over into other fields. But experts often think so. The narrower their field of knowledge the more likely they are to think so.

From somewhere, back in my youth, heard Prof say, “Manuel, when faced with a problem you do not understand, do any part of it you do understand, then look at it again.” He had been teaching me something he himself did not understand very well—something in math—but had taught me something far more important, a basic principle.

Get a shot off fast. This upsets him long enough to let you make your second shot perfect.

Had that wordy vacuum skull thought what this would do to every critical figure in science and engineering? … Throw away every book, table, instrument, and start over? I know that some of my ancestors did that in switching from old English units to MKS—but they did it to make things easier.

If it can’t be expressed in figures, it is not science; it is opinion.

It has long been known that one horse can run faster than another—but which one? Differences are crucial.

It is better to copulate than never.

It is said that God notes each sparrow that falls. And so He does … because the Sparrow is God. And when a cat stalks a sparrow both of them are God, carrying out God’s thoughts.

Magic is not science, it is a collection of ways to do things — ways that work but often we don’t know why.

Magic … is a symbol for any process not understood.

Men are more sentimental than women. It blurs their thinking.

Most “scientists” are bottle washers and button sorters.

Moving parts in rubbing contact require lubrication to avoid excessive wear. Honorifics and formal politeness provide lubrication where people rub together.

Much like engineering. Design by theory, then beef it up anyhow.

No storyteller has been able to dream up anything as fantastically unlikely as what really does happen in this mad Universe.

Nursing does not diminish the beauty of a woman’s breasts; it enhances their charm by making them look lived in and happy.

Of all the strange “crimes” that humanity has legislated out of nothing, “blasphemy” is the most amazing—with “obscenity” and “indecent exposure” fighting it out for second and third place.

One man’s “magic” is another man’s engineering. “Supernatural” is a null word.

Revolution is a science only a few are competent to practice. It depends on correct organization and, above all, on communications. … Correctly organized and properly timed it is a bloodless coup. Done clumsily … the result is civil war, mob violence, purges, terror.

The difference between science and the fuzzy subjects is that science requires reasoning while those other subjects merely require scholarship.

The earth is simply too small and fragile a basket for the human race to keep all its eggs in.

The greatest productive force is human selfishness.

The phrase is self-contradictory; “sense” is never “common”.

The truth of a proposition has nothing to do with its credibility. And vice versa.

The universe is what it is and can’t be changed by jiggery-pokery. It works by exact rules, like a machine. … Natural law never takes a holiday. The invariability of natural law is the cornerstone of science.

There are hidden contradictions in the minds of people who “love Nature” while deploring the “artificialities” with which “Man has spoiled ‘Nature.’” The obvious contradiction lies in their choice of words, which imply that Man and his artifacts are not part of “Nature”—but beavers and their dams are.

There are three schools of magic. One: State a tautology, then ring the changes on its corollaries; that’s philosophy. Two: Record many facts. Try to find a pattern. Then make a wrong guess at the next fact; that’s science. Three: Be aware that you live in a malevolent Universe controlled by Murphy’s Law, sometimes offset by Brewster’s Factor; that’s engineering.

There is no conclusive evidence of life after death. But there is no evidence of any sort against it. Soon enough you will know. So why fret about it?

There ought not to be anything in the whole universe that man can't poke his nose into—that’s the way we’re built and I assume that there's some reason for that.

This Universe never did make sense; I suspect that it was built on government contract.

To stay young requires unceasing cultivation of the ability to unlearn old falsehoods.

Touch is the most fundamental sense. A baby experiences it, all over, before he is born and long before he learns to use sight, hearing, or taste, and no human ever ceases to need it.

What happens when you place an insupportable strain on a mass, such that it cannot remain where it is? While leaving it nowhere to go? This is … the oldest proto-paradox, the one about the irresistible force and the immovable body. The mass implodes. It is squeezed out of its own world into some other.

When an apparent fact runs contrary to logic and common sense, it’s obvious that you have failed to interpret the fact correctly.

When faced with a problem you do not understand, do any part of it you do understand and then look at it again.

Wisdom is not additive; its maximum is that of the wisest man in a given group.

You live and learn. Or you don’t live long.

Your enemy is never a villain in his own eyes. Keep this in mind; it may offer a way to make him your friend. If not, you can kill him without hate—and quickly.

“Logic” proved that airplanes can’t fly and that H-bombs won’t work and that stones don’t fall out of the sky. Logic is a way of saying that anything which didn't happen yesterday won't happen tomorrow.