"A few years ago, I stumbled across an ancient book on expert systems, because I find reading technology books from the 1980s enlightening. One of the points the book stressed was that an expert system had two jobs: the first was to make a decision within its area of expertise, but the second was *to be able to explain its reasoning*. The output isn't useful if it can't be justified." (from http://thedailywtf.com/articles/the-oracle-effect)
[ponders neural networks]