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.

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.

Bugs lurk in corners and congregate at boundaries.

In programming, it’s often the buts in the specification that kill you.

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

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

Software never was perfect and won't get perfect. But is that a license to create garbage? The missing ingredient is our reluctance to quantify quality.