Knuth Quotes & Sayings

I can't be as confident about computer science as I can about biology. Biology easily has 500 years of exciting problems to work on. It's at that level. — Donald Knuth

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. — Donald Ervin Knuth

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. — Donald Knuth

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. — Donald Knuth

Any inaccuracies in this index may be explained by the fact that it has been prepared with the help of a computer. — Donald Knuth

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. — Donald Knuth

Trees sprout up just about everywhere in computer science ... — Donald Knuth

If you optimize everything, you will always be unhappy. — Donald Knuth

I think people who write programs do have at least a glimmer of extra insight into the nature of God ... because creating a program often means that you have to create a small universe — Donald Knuth

Overstimulation has been the real drawback. I need to find ways to stop thinking about analysis of algorithms, in order to do various other things that human beings ought to do. — Donald Ervin Knuth

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. — Donald Knuth

The book Dynamic Programming by Richard Bellman is an important, pioneering work in which a group of problems is collected together at the end of some chapters under the heading "Exercises and Research Problems," with extremely trivial questions appearing in the midst of deep, unsolved problems. It is rumored that someone once asked Dr. Bellman how to tell the exercises apart from the research problems, and he replied: "If you can solve it, it is an exercise; otherwise it's a research problem." — Donald Knuth

A mathematical formula should never be "owned" by anybody! Mathematics belong to God. — Donald Knuth

Programs are meant to be read by humans and only incidentally for computers to execute. — Donald Ervin Knuth

The most important thing in the kitchen is the waste paper basket and it needs to be centrally located. — Donald Knuth

From now on whenever I read a math book, I'm going to try to figure out by myself how everything was done, before looking at the solution. Even if I don't figure it out, I think I'll be able to see the beauty of a proof then. — Donald E. Knuth

Instead of concentrating just on finding good answers to questions, it's more important to learn how to find good questions! — Donald E. Knuth

The best practice is inspired by theory. — Donald Knuth

Whenever the C++ language designers had two competing ideas as to how they should solve some problem, they said, "OK, we'll do them both". So the language is too baroque for my taste. — Donald Knuth

It is much more rewarding to do more with less. — Donald Knuth

For his major contributions to the analysis of algorithms and the design of programming languages, and in particular for his contributions to the "art of computer programming" through his well-known books in a continuous series by this title. — Donald Knuth

My general working style is to write everything first with pencil and paper, sitting beside a big wastebasket. Then I use Emacs to enter the text into my machine. — Donald Knuth

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

The manuals we got from IBM would show examples of programs and I knew I could do a heck of a lot better than that. So I thought I might have some talent. — Donald Knuth

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

By understanding a machine-oriented language, the programmer will tend to use a much more efficient method; it is much closer to reality. — Donald Knuth

I define UNIX as 30 definitions of regular expressions living under one roof. — Donald Knuth

We should continually be striving to transform every art into a science: in the process, we advance the art. — Donald Knuth

The designer of a new system must not only be the implementor and the first large-scale user; the designer should also write the first user manual ... If I had not participated fully in all these activities, literally hundreds of improvements would never have been made, because I would never have thought of them or perceived why they were important. — Donald Knuth

The process of preparing programs for a digital computer is especially attractive, not only because it can economically and scientifically rewarding, but also because it can be an aesthetic experience much like composing poetry or music. — Donald Knuth

Science is what we understand well enough to explain to a computer; art is everything else. — Donald Ervin Knuth

In fact, my main conclusion after spending ten years of my life working on the T E X project is that software is hard. It's harder than anything else I've ever had to do. — Donald Knuth

Jonathon stretched his arms, like he was reading himself for exercise. He leaned back and asked, "Why are you doing this?"
Robin was a bit surprised by the blunt question. "Doing what? Laying here, strapped to this table? I'll be honest, I've asked myself the same question. — Jaron Lee Knuth

I've never been a good estimator of how long things are going to take. — Donald Knuth

In fact what I would like to see is thousands of computer scientists let loose to do whatever they want. That's what really advances the field. — Donald Knuth

These machines have no common sense; they have not yet learned to "think," and they do exactly as they are told, no more and no less. This fact is the hardest concept to grasp when one first tries to use a computer — Donald Knuth

The best theory is inspired by practice. — Donald Knuth

When certain concepts of TeX are introduced informally, general rules will be stated; afterwards you will find that the rules aren't strictly true. In general, the later chapters contain more reliable information than the earlier ones do. The author feels that this technique of deliberate lying will actually make it easier for you to learn the ideas. Once you understand a simple but false rule, it will not be hard to supplement that rule with its exceptions. — Donald Knuth

How can you own [ ... ] numbers? Numbers belong to the world. — Donald Knuth

I remember that mathematicians were telling me in the 1960s that they would recognize computer science as a mature discipline when it had 1,000 deep algorithms. I think we've probably reached 500. — Donald Knuth

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

It would be nice if we could design a virtual reality in Hyperbolic Space, and meet each other there. — Donald Knuth

Nearly every example of faulty reasoning that has been published is accompanied by the phrase "of course" or its equivalent. — Donald Ervin Knuth

The hardest thing is to go to sleep at night, when there are so many urgent things needing to be done. A huge gap exists between what we know is possible with today's machines and what we have so far been able to finish. — Donald Knuth

TeX has found at least one bug in every Pascal compiler it's been run on, I think, and at least two in every C compiler — Donald Knuth

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

Premature optimization is the root of all evil. - Donald E. Knuth [ — Joshua Bloch

Deep within the web of pavement and steel, a young boy and girl scurried past an old man, his outdated mechanical limbs shaking and twitching like an addict without a fix. He scowled at the hoodlums, scratching the hole in his face where his nose used to be, sold long ago as a cheap replacement part for someone slightly richer than he was. — Jaron Lee Knuth

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

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

God is a challenge because there is no proof of his existence and therefore the search must continue. — Donald Knuth

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% — Donald Knuth

I try to learn certain areas of computer science exhaustively; then I try to digest that knowledge into a form that is accessible to people who don't have time for such study. — Donald Knuth

An algorithm must be seen to be believed. — Donald Ervin Knuth

[The Euclidean algorithm is] the granddaddy of all algorithms, because it is the oldest nontrivial algorithm that has survived to the present day. — Donald Knuth

Programming is legitimate and necessary academic endeavour. — Donald Knuth

The designer of a new kind of system must participate fully in the implementation. — Donald Knuth

I'm obsessively detail-oriented. — Donald Knuth

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. — Donald Knuth

I can't go to a restaurant and order food because I keep looking at the fonts on the menu. — Donald Knuth

The whole thing that makes a mathematician's life worthwhile is that he gets the grudging admiration of three or four colleagues. — Donald Knuth

One of the most important lessons, perhaps, is the fact that SOFTWARE IS HARD. From now on I shall have significantly greater respect for every successful software tool that I encounter. During the past decade I was surprised to learn that the writing of programs for TeX and Metafont proved to be much more difficult than all the other things I had done (like proving theorems or writing books). The creation of good software demand a significiantly higher standard of accuracy than those other things do, and it requires a longer attention span than other intellectual tasks. — Donald Knuth

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. — Donald Knuth

My first program taught me a lot about the errors that I was going to be making in the future, and also about how to find errors. That's sort of the story of my life, making errors and trying to recover from them. I try to get things correct. I probably obsess about not making too many mistakes. — Donald Knuth

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

I currently use Ubuntu Linux, on a standalone laptop - it has no Internet connection. I occasionally carry flash memory drives between this machine and the Macs that I use for network surfing and graphics; but I trust my family jewels only to Linux. — Donald Knuth

The sun comes up just about as often as it goes down, in the long run, but this doesn't make its motion random. — Donald Knuth

If you think you're a really good programmer ... read Knuth's Art of Computer Programming ... You should definitely send me a resume if you can read the whole thing. — Bill Gates

The five stages of model development. - Donald Knuth, Stanford computer scientist Knuth discovered that computer program development goes through five stages. These steps also apply to building models, and I rigorously adhere to them in my consulting work. 1. Decide what you want the model to do. 2. Decide how to build the model. 3. Build the model. 4. Debug the model. 5. Trash stages 1 through 4 and start again, now that you know what you really wanted in the first place. Once you realize that step 5 is inevitable, you become more willing to discard bad models early rather than continually to patch them up. In fact, I recommend getting to step 5 many times by building an evolving set of prototypes. This is consistent with an emerging style of system development known as Extreme Programming.2 To get a large model to work you must start with a small model that works, not a large model that doesn't work. - Alan Manne, Stanford energy economist — Sam L. Savage

The language in which we express our ideas has a strong influence on our thought processes. — Donald Knuth

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. — Donald Knuth

Science is knowledge which we understand so well that we can teach it to a computer; and if we don't fully understand something, it is an art to deal with it. — Donald Knuth

I decry the current tendency to seek patents on algorithms. There are better ways to earn a living than to prevent other people from making use of one's contributions to computer science. — Donald Knuth

Methods are more important than facts. The educational value of a problem given to a student depends mostly on how often the thought processes that are invoked to solve it will be helpful in later situations. It has little to do with how useful the answer to the problem may be. On the other hand, a good problem must also motivate the students; they should be interested in seeing the answer. Since students differ so greatly, I cannot expect everyone to like the problems that please me. — Donald Knuth

The important thing, once you have enough to eat and a nice house, is what you can do for others, what you can contribute to the enterprise as a whole. — Donald Knuth

I have a hunch that the unknown sequences of DNA will decode into copyright notices and patent protections. — Donald Knuth

It's not really fun listening to an insane person. Do you realize that? You're only entertaining yourself. Not much of a host, if you don't mind my critique. — Jaron Lee Knuth

The most important thing in the programming language is the name. A language will not succeed without a good name. I have recently invented a very good name and now I am looking for a suitable language. — Donald Knuth

Meta-design is much more difficult than design; it's easier to draw something than to explain how to draw it. — Donald Knuth

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 eachother, like a wall of mini stones. — Donald Knuth

There's ways to amuse yourself while doing things and thats how I look at efficency. — Donald Knuth