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.

I was eventually persuaded of the need to design programming notations so as to maximize the number of errors which cannot be made, or if made, can be reliably detected at compile time.

An ultimate joint challenge for the biological and the computational sciences is the understanding of the mechanisms of the human brain, and its relationship with the human mind.

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

I call it my billion-dollar mistake. It was the invention of the null reference in 1965.

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.

The job of formal methods is to elucidate the assumptions upon which formal correctness depends.