Archive for February 7th, 2011

February 7, 2011

Purpose (6) – background

by Neil Rickert

For this post, I want to go over how I became interested in purpose.

It all started with a personal interest in understanding how humans learn, so I spent some time studying the problem of learning.  I tried to combine two approaches.  One of those was to use the methods of AI, which would require modeling learning as a computational problem.  The other was to look at natural learning such as occurs in biological systems.  The aim was that ideas I might glean from looking at natural learning systems could perhaps provide guidance for computation learning.

Computers are versatile, so when you have a specific problem, you can usually come up with a way of solving it.  But the general problem for learning is that we don’t start with specific problems; we somehow just learn without being told what to learn.  And the general problem that I ran into was one of setting direction.

One of my grad school professor, S. Kakutani, would sometimes ask “Pick a number. Square it.  Is that a theorem?”  The idea was that if I pick a large number x, and square it (multiply it by itself) to yield y, then the statement “y is a perfect square” is a true statement that has probably never been stated before.  But no mathematician would consider that a worthy result.  We don’t just come up with true beliefs; we come up with interesting true beliefs.  And that leaves the difficulty of deciding what is interesting.  Hubert Dreyfus, a sometime critic of AI, expressed the general problem this way.

Using Heidegger as a guide, I began to look for signs that the whole AI research program was degenerating. I was particularly struck by the fact that, among other troubles, researchers were running up against the problem of representing significance and relevance – a problem that Heidegger saw was implicit in Descartes’ understanding of the world as a set of meaningless facts to which the mind assigned what Descartes called values and John Searle now calls function predicates.

So I went looking for sources of such direction.  I remember some particularly useful online discussions with Chris Malcolm of Edinburgh University, and those discussions were part of what set me looking for a good account of purpose, eventually leading me to the position that I have been presenting in this series of posts.