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.

A most important, but also most elusive, aspect of any tool is its influence on the habits of those who train themselves in its use. If the tool is a programming language this influence is, whether we like it or not, an influence on our thinking habits.... A programming language is a tool that has profound influence on our thinking habits.

The prisoner falls in love with his chains.

If you want more effective programmers, you will discover that they should not waste their time debugging, they should not introduce the bugs to start with.

Simplicity and elegance are unpopular because they require hard work and discipline to achieve and education to be appreciated.

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

There is very little point in trying to urge the world to mend its ways as long as that world is still convinced that its ways are perfectly adequate.