The failure mode that goes with the Unix tradition's insistence on simplicity is that Unix programmers often talk (and sometimes even behave) as though all optional complexity is accidental. More than this, there is a strong bias in the Unix tradition toward removing features rather than accepting optional complexity.

The case for this attitude is easy to make (indeed, we spend much of this book making it). Clean minimalism makes us feel virtuous on many levels, and designing for it is a valuable counter to the natural tendency of software systems to develop ever-more-elaborate encrustations of ill-considered features. But computing resources and human thinking time, like wealth, find their justification not in being hoarded but in being spent. As with other forms of asceticism, one has to ask when design minimalism stops being a valuable form of self-discipline and starts being a mere hair shirt — a way to indulge those feelings of virtue at the expense of actually using that wealth to get work done.

This is a perilous question, all too easily turned into an argument for abandoning good design discipline altogether. Unix old hands often shy away from it, fearing that failing to hold the hardest possible line against complexity and bloat will lead us inexorably to damnation. But it's also a necessary question. We'll tackle it directly when analyzing this chapter's case studies.