A design remedy that prevents bugs is always preferable to a test method that discovers them.

More than the act of testing, the act of designing tests is one of the best bug preventers known.

Second law: The complexity barrier. Software complexity (and therefore that of bugs) grows to the limits of our ability to manage that complexity.

Extra features were once considered desirable. We now recognize that 'free' features are rarely free. Any increase in generality that does not contribute to reliability, modularity, maintainability, and robustness should be suspected.

One of the saddest sights to me has always been a human at a keyboard doing something by hand that could be automated. It's sad but hilarious.

First law: The pesticide paradox. Every method you use to prevent or find bugs leaves a residue of subtler bugs against which those methods are ineffective.

If the objective of testing were to prove that a program is free of bugs, then not only would testing be practically impossible, but it would also be theoretically impossible.