The purpose of abstraction is not to be vague, but to create a new semantic level in which one can be absolutely precise.

Don't blame me for the fact that competent programming, as I view it as an intellectual possibility, will be too difficult for the average programmer, you must not fall into the trap of rejecting a surgical technique because it is beyond the capabilities of the barber in his shop around the corner.

APL is a mistake, carried through to perfection.

We are all shaped by the tools we use, in particular: the formalisms we use shape our thinking habits, for better or for worse, and that means that we have to be very careful in the choice of what we learn and teach, for unlearning is not really possible.

Besides a mathematical inclination, an exceptionally good mastery of one's native tongue is the most vital asset of a competent programmer.

In their capacity as a tool, computers will be but a ripple on the surface of our culture. In their capacity as intellectual challenge, they are without precedent in the cultural history of mankind.

If we wish to count lines of code, we should not regard them as "lines produced" but as "lines spent."