3 why test software?

Testing must compete for resources
Is there ANYONE who ALWAYS writes perfect code?
Software testing allows catching of defects (and enhancements) early, so cheaper to handle.
Track and prioritize defects (and enhancements)

In testing, who is more important that the customer?
Is the testing team allowed to say NO?
Testing requires a 'whole system' perspective.

Quality is more than just fixing bugs.
Choice of language makes a difference.
Pair programming improves quality
(Even explaining your code to your dog has been shown to improve quality)

Goal is to minimize risk.