We all know that the only mental tool by means of which a very finite piece of reasoning can cover a myriad cases is called abstraction; as a result the effective exploitation of his powers of abstraction must be regarded as one of the most vital activities of a competent programmer. In this connection it might be worth-while to point out that the purpose of abstracting is not to be vague, but to create a new semantic level in which one can be absolutely precise.

- Edsger W. Dijkstra – ACM Turing Lecture: “The Humble Programmer”

This was written about programming and AI, but in my mind, it applies to many forms of abstraction, including art.