Donald Knuth Quotes

Programming is the art of telling another human being what one wants the computer to do.

Computer programming is an art, because it applies accumulated knowledge to the world, because it requires skill and ingenuity, and especially because it produces objects of beauty. A programmer who subconsciously views himself as an artist will enjoy what he does and will do it better.

Always remember, however, that there’s usually a simpler and better way to do something than the first way that pops into your head.

We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil.

Programs are meant to be read by humans and only incidentally for computers to execute.

Computers are good at following instructions, but not at reading your mind.

If you find that you're spending almost all your time on theory, start turning some attention to practical things; it will improve your theories. If you find that you're spending almost all your time on practice, start turning some attention to theoretical things; it will improve your practice.

When you write a program, think of it primarily as a work of literature. You're trying to write something that human beings are going to read. Don't think of it primarily as something a computer is going to follow. The more effective you are at making your program readable, the more effective it's going to be: You'll understand it today, you'll understand it next week, and your successors who are going to maintain and modify it will understand it.

Beware of bugs in the above code; I have only proved it correct, not tried it.

If you optimize everything, you will always be unhappy.

It is much more rewarding to do more with less.

Premature optimization is the root of all evil.

Science is what we understand well enough to explain to a computer. Art is everything else we do.

The enjoyment of one's tools is an essential ingredient of successful work.

Email is a wonderful thing for people whose role in life is to be on top of things. But not for me; my role is to be on the bottom of things. What I do takes long hours of studying and uninterruptible concentration.

An algorithm must be seen to be believed.

The psychological profiling [of a programmer] is mostly the ability to shift levels of abstraction, from low level to high level. To see something in the small and to see something in the large.

Everyday life is like programming, I guess. If you love something you can put beauty into it.

The best programs are written so that computing machines can perform them quickly and so that human beings can understand them clearly. A programmer is ideally an essayist who works with traditional aesthetic and literary forms as well as mathematical concepts, to communicate the way that an algorithm works and to convince a reader that the results will be correct.

People think that computer science is the art of geniuses but the actual reality is the opposite, just many people doing things that build on each other, like a wall of mini stones.

The best theory is inspired by practice.

Programmers waste enormous amounts of time thinking about, or worrying about, the speed of noncritical parts of their programs, and these attempts at efficiency actually have a strong negative impact when debugging and maintenance are considered. We should forget about small efficiencies, say about 97% of the time: premature optimization is the root of all evil. Yet we should not pass up our opportunities in that critical 3%.

People who are more than casually interested in computers should have at least some idea of what the underlying hardware is like. Otherwise the programs they write will be pretty weird.

Random numbers should not be generated with a method chosen at random

AI has by now succeeded in doing essentially everything that requires 'thinking' but has failed to do most of what people and animals do 'without thinking'-that, somehow, is much harder.