Donald Knuth Quotes

You can measure a programmer's perspective by noting his attitude on the continuing vitality of FORTRAN.

There is no doubt that the grail of efficiency leads to abuse. 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%. A good programmer will not be lulled into complacency by such reasoning, he will be wise to look carefully at the critical code; but only after that code has been identified. It is often a mistake to make a priori judgments about what parts of a program are really critical, since the universal experience of programmers who have been using measurement tools has been that their intuitive guesses fail.

FORTRAN, the infantile disorder, by now nearly 20 years old, is hopelessly inadequate for whatever computer application you have in mind today: it is now too clumsy, too risky, and too expensive to use.

You can't drop concepts. You can only shine a little flashlight on them as you do inquiry, an you see that what you thought was true wasn't. And when the truth is seen, there's nothing you can do to make the lie true for you again.

Comes a Time when the blind man takes your hand says DON'T YOU SEE?

Of the Surface of Things In my room, the world is beyond my understanding; But when I walk I see that it consists of three or four Hills and a cloud.

Reason and intellect are opening wedges in an understanding of reality.

We have this huge, massive information, but what is it that matters? What doesn't matter? What makes sense, what doesn't make sense? You have to have a framework for understanding and of interpretation in order to make use of the information.

Quite frankly, even if the choice of C were to do *nothing* but keep the C++ programmers out, that in itself would be a huge reason to use C.

Science has to do with facts, art with phenomena. To science, phenomena are of use only as they lead to facts; and to art, facts are of use only as they lead to phenomena.

The role of the scholar is to destroy chimeras, that of the statesman is to make use of them.

What men have seen they know. . . .

Our reality is influenced by our notions about reality, regardless of the nature of those notions

Words reduce reality to something the human mind can grasp, which isn’t very much.

Having one's eyes opened doesn't make one grateful.

The need of reason is not inspired by the quest for truth but by the quest for meaning. And truth and meaning are not the same. The basic fallacy , taking precedence over all specific metaphysical fallacies, is to interpret meaning on the model of truth.

The one created thing which we cannot look at is the one thing in the light of which we look at everything.

Though Anne was born in Alabama and schooled in Mississippi, she had traveled North, and, like many Southerners, gained a theoretical understanding of the concept of cold. But the mind is an overprotective parent. What it doesn't care for, it hides. Like many inhabiting the subtropics, Anne had repressed the reality of subzero mercury.

It used to be the program's purpose to instruct our computers; it became the computer's purpose to execute our programs.

The best antidote to prejudice is reality.

Talk is cheap. Show me the code.

When the mind's eye rests on objects illuminated by truth and reality, it understands and comprehends them, and functions intelligently; but when it turns to the twilight world of change and decay, it can only form opinions, its vision is confused and its beliefs shifting, and it seems to lack intelligence.

Empathy takes time, and efficiency is for things, not people.

To understand the actual world as it is, not as we should wish it to be, is the beginning of wisdom.

We just do not see how very specialized the use of "I know" is.