Okay, this is about as "out there" as art gets. I found this fascinating article by Philip Galanter, of the Interactive Telecommunications Program, New York City, USA.
The title of the article is:
What is Generative Art? Complexity Theory as a Context for Art Theory.
Here is the abstract from the paper:
In this paper an attempt is made to offer a definition of generative art that is inclusive and provides fertile ground for both technical and art theoretical development. First the use of systems is identified as a key element in generative art. Various ideas from
complexity theory are then introduced. It is noted that systems exist on a continuum from the highly ordered to the highly disordered. Citing examples from information
theory and complexity science, it is noted that highly ordered and highly disordered systems are typically viewed as simple, and complex systems exhibit both order and disorder. This leads to the adoption of effective complexity, order, and disorder as organizing principles in the comparison of various generative art systems. This inclusive view leads to the somewhat surprising observation that generative art is as old as art itself. A number of specific artists and studies are discussed within this systems and complexity theory influenced paradigm. Finally a number of art theoretical questions are introduced to exercise the suggested generative art definition and implicit paradigm.
As I understand this paper, generative art follows the guidelines of complexity science and, more specifically, Joshua Epstein's work on generative computational social science. Here, the idea is that art is generated from the bottom-up by some iterative artistic process, followed to its logical conclusions, forming some type of emergent system. The rules can be anything--paint right, then left, then up, each turn of the paint being a different color, to produce some painting.
These paintings can be highly ordered or fall into total chaos. One can catalogue these various systems paintings, and so forth. In my mind, Chuck Close's abstract portraits is a good example of a highly ordered complex system. Galanter may disagree. Either way, it is a very interesting and provocative paper worth reading.