Physical Computation: A Mechanistic Account

by Gualtiero Piccinini

Gualtiero Piccinini articulates and defends a mechanistic account of concrete, or physical, computation. A physical system is a computing system just in case it is a mechanism one of whose functions is to manipulate vehicles based solely on differences between different portions of the vehicles according to a rule defined over the vehicles. The Nature of Computation discusses previous accounts of computation and argues that the mechanistic account is better.Many kinds of computation are explicated, such as digital vs. analog, serial vs. parallel, neural network computation, program-controlled computation, and more. Piccinini argues that computation does not entail representation or information processing although information processing entails computation.Pancomputationalism, according to which every physical system is computational, is rejected. A modest version of the physical Church-Turing thesis, according to which any function that is physically computable is computable by Turing machines, is defended.

Genres: Philosophy, Computer Science, Computers, Physics, Nonfiction

280 pages, Kindle Edition

First published July 2, 2015

About the author

University of Missouri - St. Louis, USA

Reviews

[Jhc · Rating 5 out of 5]

The best book I've read to date on the debate about physical computation. Even if you don't like the mechanical approach, the clarity with which the author presents and disentangles the debate makes this a must-read for anyone looking for an introduction to the field.

[H Gultiano]

I was looking for books on mechanical computing, crunching numbers with clockwork gears, fluid in tubes, or anything other than electricity on circuit boards, but found (downloaded off of libgen) this one instead: a philosophy book on what computation actually is.

If anyone's really interested in scrutinizing the ideas that "everything is a computer" -- which the author rejects, because it makes the concept of computing effectively meaningless -- or "the brain is a computer," then I would recommend this book. I'm interested in the latter because there are whole fields of neuroscience based on that idea.

Piccinini clearly goes over what "computing" must mean on a physical-functional level, aka as mechanism, and shows how, if theories of cognition are to use that comparison, the brain/neurons must be shown to to do what computing mechanisms do, whether analog or digital or hybrid. He doesn't really get into how that idea is circular, computers were designed to replicate a mental process and heavily inspired by neuroscience in their early designs by von Neumann and others. This is an idea I probably could write more about myself.

Clearly defining the idea of "computation" really supports any [critical] engagement with the brain-as-computer metaphor. Even though there's not really any suggestion of this being a central theme of the book in the title, it's the main reason I'd recommend this book. Computer scientists would probably not care as much to pedantically pick apart the borders of their discipline, and people in the pancomputationalist camp often seem like they're religiously adhered to their beliefs that the universe is a giant computer, so I don't care to waste energy on arguing with them.

[Shubhang Goswami · Rating 5 out of 5]

If you are interested in the Philosophy of Computation, this is a must read.
After defining the desiridata, the author for the next 5 or 6 chapters refutes other arguments of computation. Starting from Chapter 7 we get the author's theory of computation. Then follow the implementation of his theory on digital, analog and neural computations.

It is quite thorough, but the author uses a lot of examples that aid in reading.