Black-Box Testing Quotes

“Anything written by people has bugs. Not testing something is equivalent to asserting that it's bug-free. Programmers can't think of everything especially of all the possible interactions between features and between different pieces of software. We try to break software because that's the only practical way we know of to be confident about the product's fitness for use.”
― Boris Beizer, Black-Box Testing: Techniques for Functional Testing of Software and Systems