Archive for the ‘extension’ Category

090226 (originally 081224) – Is all computation epiphenomenal

Thursday, February 26th, 2009

081224

Is all computation epiphenomenal?

[090226]

Is COMPUTATION a concept with no extension?  In other words does computation always require an intensional context?  Maybe this is what Searle is getting at when he insists that computation is in the mind of the beholder.  It would seem that there are quite a few such concepts, e.g., METAPHYSICS, CAUSE, TRUTH, ONTOLOGY, EPISTEMOLOGY, FREEDOM, HAPPINESS, etc.  Is it the case that only concepts whose content is physical actually have an extension?  Is even that consolation ephemeral?  Does the unending cycle that is the external environment acting upon the internal environment acting upon the external environment acting upon the internal environment … ad infinitum necessarily entail only probabilistic (Bayesian) certainties?  Or does it entail only intensional certainties (whatever that may mean)?

Fodor 2008 (n.18) says that ‘it’s probable that …’ is extensional and unable to reconstruct intensionality in any form.  “An intensional context is one in which the substitution of coextensive expressions is not valid.”  (n.1)  But isn’t it the case that ‘it’s probable that …’ becomes intensional if ‘…’ is replaced by an intensional attribute as, for example if Oedipus were to say, “It’s probable that my mother dwells many leagues hence.”

Intensionality is about invariants and irrelevancies, about fixed and free parameters that map via a characteristic transduction process to and from an environmental state that is extensional content (where coextensive expressions are indistinguishable).  Intensionality develops in both evolutionary and epigenetic time.  It is real easy to get confused about what goes on here.  That seems to be what the idea of ‘rigid designators’ is about.

In the context of computer science, the programmer has intentions, but the program has only intensions (with an s).  Or at least that is the way things seem now.[1]  The fact that we are willing to accept in this statement the attribution of intentionality to the programmer is significant because it suggests that the boundary between intentionality and intensionality (with an s) may shift about depending on the context of the polemic.  This is a puzzling thought.  Shouldn’t the intentionality / intensionality distinction be essential?  It might be, for example that Oedipus the programmer writes an algorithm to determine, based on some kind of survey data, which women are mothers and of whom.  The (incorrect) program he writes looks like the following:

For each woman w do
   If w is not married
      Then w is not a mother
   Else
      If w has children c
         Then w is the mother of c
      Else
         w is not a mother
End do

It’s not that Oedipus thinks that an unmarried woman with children is not a mother; he just writes the program incorrectly.  So, the extension of the world-at-large’s intensional concept of MOTHER-OF[2] differs from the extension of Oedipus’s intensional concept of MOTHER-OF, which differs from the extension of the intensional concept MOTHER-OF that his program implements.  This just goes to show that the wise child knows his own mother and that one person’s extension may be another’s intension.

‘WATER is H2O’ and ‘it is probable that WATER is H2O’

This is an epistemological problem. Epistemological WATER is epistemological H2O only insofar as platonic WATER and platonic H2O (if such there be) have interacted in the context of the history of the universe   that includes the evolution of human beings capable of framing the concepts and doing the science necessary to connect the two.  But the problem is the same as the one Fodor 2008 raises in relation to evolution and the essential difference between selection and selection for.  Muddy water and water containing other impurities aside, H2O arguably isn’t a natural kind, since there are three naturally occurring isotopes of hydrogen and more than three naturally occurring isotopes of oxygen and all of those can be in distinct quantum states that can, given appropriate laboratory equipment, be physically distinguished from one another.

As Fodor 2008 observes in a slightly different context, “what’s selected underdetermines what’s selected for because actual outcomes always underdetermine intentions.”  (p.6)  This is as true when doing science as it is when doing evolution: what’s observed underdetermines what happened because actual observations always underdetermine total postdiction of experimental conditions.  You can refine a bit, but you can’t pin down, especially when you try to pin down things so precisely that you are in the realm of Heisenberg uncertainty and quantum mechanical indeterminacy.  So precision as we commonly understand it is a platonic ideal without a real world correlate and, more to the point, an intensional process that doesn’t have an extension.

Fodor 2008 further observes (p.9) that “who wins a t1 versus t2 competition is massively context sensitive.”  Ditto, whether WATER is H2O or XYZ or both or neither.

===================== Notes =====================

[1]  This is the nature of many a program bug.  The programmatic identification of content from transduced data (the type that the code assigns to those data) may not accurately track the programmer’s intended identification of that content even if the transduction is accurate and the transduced data are sufficient to make the determination.  If the programmer errs in writing the type determination code, the type determination the program makes will err (from the programmer’s standpoint), but no inconsistency will be detectable within the program.

[2] Which includes that Jocasta is the mother of Oedipus.