FRIAM and CAUSALITY (was NOT "complexity and emergence")

Posted by David Eric Smith on
URL: http://friam.383.s1.nabble.com/FRIAM-and-CAUSALITY-was-NOT-complexity-and-emergence-tp525402p525412.html

Hi Nick,

Given the energy (and time!) apparently available to this thread, it
is with some trepidation that I poke my head out of the weeds.  (On
the other hand, congratulations, Steve).

I like your last post about patterns, except for the strong emphasis
on psychological/mental attribution, if causality is the example we
wish to talk about.  As in the case with data compression or phase
transitions in condensed-matter physics, it is all fine that someone
notices the data redundancy or order parameter in the material.  But
this should only be possible with any reliability if such a pattern is
available in the system, to be recognized.  My typical (and probably
tiresome by now) example for the phase transitions is: give me water
at +1 deg C and -1 deg C at 1 atm pressure, and then apply any
learning algorithm you like to provide a short algorithm to ask
whatever questions I put to it about the orientation and motion of the
molecules, and how they differ in the two samples.  Maybe some
algorithms won't learn anything useful for short descriptions, but in
a fair casino I would bet that most of those that do learn anything
will learn to estimate the order parameter, and then to use it as the
starting point for quick prediction of many observables.  There simply
isn't anything else that has particularly changed between the
properties of the two samples, and everything that has changed is a
deterministic function of the order parameter, even the moments of all
the distributions for fluctuations.  And however they name it or
represent it, I expect that the predictive content of what they learn
will be more or less the same as that in what we call the order
parameter (the existence and direction of crystalline orientation).

Something like that would seem appropriate to causality, at least for
the simple forms that we largely understand, such as classical
dynamics in physics, or Pearl's boolean nets in inference.  To argue
that psychological/mental attribution is anything beyond one-of-many
possible learning processes, you would have to convince me that the
concept of causation is at root a behavioral one -- perhaps some kind
of agent-patient relation, or even something in the social domain --
and that as a result the attribution of causation by people contains
particular aspects that other learning algorithms would not typically
produce.  For astrology and a large part of the metaphor we apply to
nations and other institutions, and things of that sort, I would go
along with this.  Otherwise I counter that the pattern is "in the
thing (the process in question)", and not particularly in one learner
versus another, who try to learn about the thing.

This small point of dispute, which maybe wouldn't even bother you, is
quite in keeping with your overall assertion that repeated experience
is needed to decide whether a pattern is appropriately characterized
with the logical structure of causality (a properly contextualized if
not-x, then not-y).

Of course, having agreed with you so far, I suddenly realize that I
will probably disagree with you now and start an argument, which had I
known it, would have kept me from starting this note.  If a relation
(a compressed description of some regularity) is available in a
process to be learned, and described with the logical structure of
causality, then in what sense does the system itself care whether the
learner needs repeated exposure to learn it.  The repetition is a
feature of the needs of learning algorithms, largely irrespective of
what they are trying to learn about.  How does it do anything but
needlessly complicate my description of nature, to suppose that other
instances than this one (of some process) have anything to do with the
existence or non-existence of an aspect of the process that admits
description as causal?  If it exists, the simplest description of its
existence is whichever one omits all un-needed elements of context;
such a description would then put its existence in each instance
without further qualifications.

So causation (in ordinary material processes or appropriate branches
of information theory) is admissible in our descriptions as a property
of the thing, in each instance, and largely independent of the fact
that we should be the ones characterizing the thing; the need for
repeated exposure is a property of us, largely independent of whether
causal relation or some other pattern is what we will notice in the
thing.

Anyway, don't know if those opinions will address what you are after,
and they are probably less sophisticated than what has already been
said here.

All best,

Eric