Years ago, I was pondering the difference between science and art. People had been asking me why my books were called The Art of Computer Programming instead of The Science of Computer Programming, and I realized there's a simple explanation: Science is what we understand well enough to explain to a computer; art is everything else. Every time science advances, part of an art becomes a science, so art loses a little bit. Yet, mysteriously, art always seems to register a net gain, because as we understand more we invent more new things that we can't explain to computers. -- pg. 168.