""" Is carrying out an algorithm more like “computation” or is “building a limb”? Is a salamander’s limb “computed”? If so, who computes it, or is that a violation of the language of computation. """
From the summary of Chemero's "Radical Embodied Cognitive Science": """ Radical embodied cognitive science is a direct descendant of the American naturalist psychology of William James and John Dewey, and follows them in viewing perception and cognition to be understandable only in terms of action in the environment. Chemero argues that cognition should be described in terms of agent-environment dynamics rather than in terms of computation and representation. After outlining this orientation to cognition, Chemero proposes a methodology: dynamical systems theory, which would explain things dynamically and without reference to representation. He also advances a background theory: Gibsonian ecological psychology, “shored up” and clarified. """ Which I find helpful to juxtapose against Valiant's "Probably Approximately Correct": """ The assertion that the Halting Problem was not computable by any Turing machine was identified with the claim that it was not computable by any conceivable mechanical procedure...Extensive efforts at finding models that have greater power than Turing machines, but still correspond to what one would instinctively regard as mechanical processes, have all failed. Therefore there is now overwhelming historical evidence that Turing's notion of computability is highly robust to variation in definition. This has placed Turing computability among the most securely established theories known to science. """ Two steps in Turing's process I find worth highlighting are: 1. Abstraction of features of particular machines to the general. 2. Discovery of a limiting set of robust properties of generalized machines such that these properties could be identified universally in any sufficiently capable mechanical process. In part, I mention the question of universality because (here in the still hours of a sleepless night) I cannot help but feel that metaphors often attempt to point to universals[1]. While I am never really sure that I get non-computation in the sense of Chemero, chatting with EricC about Gibson makes me feel like I can almost see it. Where Valiant emphasizes in computation that which is universal to anything we can sensibly call mechanics, Chemero and others place the universality squarely on the side of representation, or in some extreme cases of nominalism, rejecting the universality altogether. From another perspective, a difference between these two points of view relates to the question of agency. In Valiant's description, one doesn't seem to care *what is doing the computation* as much as that a mechanical procedure is executed at all. Alternatively, Chemero is concerned with subjectivity. For him, there are well-defined agents and they have environments. As far as I can read, each disagrees terminologically on whether agent-based models compute. While Valiant is comfortable calling what these agents do in their environment a computation, Chemero is not. [1] Nick, regarding universals, while I have heard you denounce the stability of a universal, like beauty, what is your bet on computation? -- Sent from: http://friam.471366.n2.nabble.com/ - .... . -..-. . -. -.. -..-. .. ... -..-. .... . .-. . FRIAM Applied Complexity Group listserv Zoom Fridays 9:30a-12p Mtn GMT-6 bit.ly/virtualfriam un/subscribe http://redfish.com/mailman/listinfo/friam_redfish.com FRIAM-COMIC http://friam-comic.blogspot.com/ archives: http://friam.471366.n2.nabble.com/
