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.

Bugs lurk in corners and congregate at boundaries.

If you can't test it, don't build it. If you don't test it, rip it out.

Testing proves a programmer’s failure. Debugging is the programmer’s vindication.

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.

A test that reveals a bug has succeeded, not failed.

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