Subject, Object, Properties? What is Mind? What is Body? Philosophical questions are never settled but perpetually re-cognised in the flux of context, the plenum of the world. The invention of the computer has recast such perennial questions. Computer scientists know, because as programmers they engage at first hand, how difficult it is to achieve a desired effect by way of rigid rules. The hard things that have traditionally been identified with intelligence - logic, mathematics, Reason - turn out to be rather easy; but robotics, paradoxically, is not child's play. For the first time we have created something which enables us to consider thought and intention outside the epistemic difficulties of introspection. A new science implies a new phenomenon to be studied - for computer science the phenomena are not computers qua machines, nor computation qua crunching numbers, but programs. But what is a program? On the Origin of Objects starts with such questions and then asks "how the world may seem for the machines themselves not for us". And if we can ask this of machines why not also of minds and brains and people: "The point is easier to see in our own case. How we take the world to be - to consist of objects, properties and relations, or of other things, or whatever - cannot depend on how we take our minds or brains to be, since most of us do not take our minds or brains to be any way at all." [p67] The argument is developed slowly and clearly - this is very readable philosophy. Like the building of a new house on the site of one in which we are constrained to live. We proceed in parts: a temporary encampment in physics until the rest of the ontology is habitable. Smith is cautious in the use he makes of physics - and of materialism in general. Neurophysiologists know much about the wiring and biochemistry of the brain but we should not assume such knowledge will reveal much about thinking per se. For in the case of computers despite knowing enough to build the machine we still understand - "at the right explanatory level" - very little of "what the program is doing." [p148] Chapter 7 is the heart of the book: there are no objects nor knowing subjects in the "field theoretic" locus in which we "register" a world in flux. The argument is clear and strong, picking up where the early cyberneticists lost their way, with tracking: "consider a frog tracking a fly". But without frog or fly, only "a differential density mass with complex internal structure." The air between is not to be discounted because it seems transparent. "...how it is that we and perhaps frogs see flies, not electromagnetic radiation, is the registration problem in a nutshell".[p217] Smith's conclusion is that registering objects is an active process. There is thus a relation between objectifying the world, discreteness, digitality and formalism. Mathematics is an achievement, not something inherent in the nature of the world awaiting our discovery. And computers challenge our conception of what is essentially human so that: "... computer science's most important contribution to intellectual life: its development of a synthetic methodological stance toward registrational and intentional systems." [p369] Critics of programming practice have compared it to alchemy and Smith recalls the characterisation of Newton as the last of the magicians. Is this a pre-Newtonian phase, lacking "Laws", awaiting the differential calculus? Another position is suggested: "... that we are post-Newtonian, in the sense of being inappropriately wedded to a particular reductionist form of scientism, inapplicable to so rich an intentional phenomenon. Another generation of scientists may be the last thing we need. Maybe, instead, we need a new generation of magicians". [p362] Magician? Magus? Seeking the secret of how it is we "deconvolve the deixis" - plus ça change, plus c'est la même chose. The Alchemist: not a charlatan, but one possessed of much empirical wisdom stumbling after the scheme of things; as this new Science of the Artificial must do, self constructed, self referential, post-post-modern, a metaphysics for the 21st century.