Tuesday, February 22, 2011

music and computation

Gottfried Wilhelm Leibniz's view on music ('the hidden arithmetical exercise of a mind unconscious that is calculating') has (at least) two straightforward interpretations. The first one is essentially reductionist (a 'fallacy of the misplaced concreteness' according to Alfred North Whitehead) and tends to suggest that music is nothing but computation (albeit in the background/unconscious, in a less obvious way). The second interpretation of the music-calculating connection runs somehow in the opposite direction, and tends to suggest that there is more to computation than meets the eye, an ethereal/ineffable/musical/higher-order quality. At this point, one might try to revisit the spirit of some traditional Gödelian themes...
Image source: http://en.wikipedia.org/wiki/File:FortranCardPROJ039.agr.jpg

Wednesday, February 16, 2011

Hubert Dreyfus' criticism of AI

Dreyfus's critique of artificial intelligence (AI) concerns what he considers to be the four primary assumptions of AI research. The first two assumptions he criticizes are what he calls the "biological" and "psychological" assumptions. The biological assumption is that the brain is analogous to computer hardware and the mind is analogous to computer software. The psychological assumption is that the mind works by performing discrete computations (in the form of algorithmic rules) on discrete representations or symbols.

Dreyfus claims that the plausibility of the psychological assumption rests on two others: the epistemological and ontological assumptions. The epistemological assumption is that all activity (either by animate or inanimate objects) can be formalised (mathematically) in the form of predictive rules or laws. The ontological assumption is that reality consists entirely of a set of mutually independent, atomic (indivisible) facts. It's because of the epistemological assumption that workers in the field argue that intelligence is the same as formal rule-following, and it's because of the ontological one that they argue that human knowledge consists entirely of internal representations of reality.

On the basis of these two assumptions, workers in the field claim that cognition is the manipulation of internal symbols by internal rules, and that, therefore, human behaviour is, to a large extent, context free (see contextualism). Therefore a truly scientific psychology is possible, which will detail the 'internal' rules of the human mind, in the same way the laws of physics detail the 'external' laws of the physical world. But it is this key assumption that Dreyfus denies. In other words, he argues that we cannot now (and never will) be able to understand our own behavior in the same way as we understand objects in, for example, physics or chemistry: that is, by considering ourselves as things whose behaviour can be predicted via 'objective', context free scientific laws. According to Dreyfus, a context free psychology is a contradiction in terms.

Dreyfus's arguments against this position are taken from the phenomenological and hermeneutical tradition (especially the work of Martin Heidegger). Heidegger argued that, contrary to the cognitivist views on which AI is based, our being is in fact highly context bound, which is why the two context-free assumptions are false. Dreyfus doesn't deny that we can choose to see human (or any) activity as being 'law governed', in the same way that we can choose to see reality as consisting of indivisible atomic facts...if we wish. But it is a huge leap from that to state that because we want to or can see things in this way that it is therefore an objective fact that they are the case. In fact, Dreyfus argues that they are not (necessarily) the case, and that, therefore, any research program that assumes they are will quickly run into profound theoretical and practical problems. Therefore the current efforts of workers in the field are doomed to failure.

Source: Hubert Dreyfus - Wikipedia - http://en.wikipedia.org/wiki/Hubert_Dreyfus

Hubert Dreyfus on Husserl and Heidegger
Section 1 - http://www.youtube.com/watch?v=aaGk6S1qhz0

Section 2 - http://www.youtube.com/watch?v=ylKnb6WtYqU
Section 3 - http://www.youtube.com/watch?v=LgUDaml7ZJY
Section 4 - http://www.youtube.com/watch?v=QzAqfzWJTq4
Section 5 - http://www.youtube.com/watch?v=VfsKTSM5Sns

Sunday, February 6, 2011

Argument from Reason

“That grand myth which I asked you to admire a few minutes ago is not for me a hostile novelty breaking in on my traditional beliefs. On the contrary, that cosmology is what I started from. Deepening distrust and final abandonment of it long preceded my conversion to Christianity. Long before I believed Theology to be true I had already decided that the popular scientific picture at any rate was false. One absolutely central inconsistency ruins it; it is the one we touched on a fortnight ago. The whole picture professes to depend on inferences from observed facts. Unless inference is valid, the whole picture disappears. Unless we can be sure that reality in the remotest nebula or the remotest part obeys the thought--laws of the human scientist here and now in his laboratory-in other words, unless Reason is an absolute--all is in ruins. Yet those who ask me to believe this world picture also ask me to believe that Reason is simply the unforeseen and unintended by-product of mindless matter at one stage of its endless and aimless becoming. Here is flat contradiction. They ask me at the same moment to accept a conclusion and to discredit the only testimony on which that conclusion can be based. The difficulty is to me a fatal one; and the fact that when you put it to many scientists, far from having an answer, they seem not even to understand what the difficulty is, assures me that I have not found a mare's nest but detected a radical disease in their whole mode of thought from the very beginning. The man who has once understood the situation is compelled henceforth to regard the scientific cosmology as being, in principle, a myth; though no doubt a great many true particulars have been worked into it.”
(C. S. Lewis - as cited in Is Theology Poetry - GregorianStorage, 1/07/2011)
Image source: http://en.wikipedia.org/wiki/File:Hubble_-_infant_galaxy.jpg
Argument from Reason - Wikipedia.
C. S. Lewis' The cardinal difficulty of naturalism