Inside every large program is a small program struggling to get out.

I couldn't resist the temptation to put in a null reference, simply because it was so easy to implement. This has led to innumerable errors, vulnerabilities, and system crashes, which have probably caused a billion dollars of pain and damage in the last forty years.

You cannot teach beginners top-down programming, because they don't know which end is up.

The real value of tests is not that they detect bugs in the code but that they detect inadequacies in the methods, concentration, and skills of those who design and produce the code.

In the development of the understanding of complex phenomena, the most powerful tool available to the human intellect is abstraction. Abstraction arises from the recognition of similarities between certain objects, situations, or processes in the real world and the decision to concentrate on these similarities and to ignore, for the time being, their differences.

Here is a language so far ahead of its time, that it was not only an improvement on its predecessors, but also on nearly all its successors.

There are two ways of constructing a software design: One way is to make it so simple that there are obviously no deficiencies, and the other way is to make it so complicated that there are no obvious deficiencies. The first method is far more difficult.