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From: abbott@aerospace.aero.org (Russell J. Abbott)
Newsgroups: comp.ai.philosophy
Subject: emergence
Message-ID: <87759@aerospace.AERO.ORG>
Date: 5 Oct 90 20:44:46 GMT
Sender: news@aerospace.aero.org
Reply-To: abbott@antares.UUCP (Russell J. Abbott)
Organization: The Aerospace Corporation, El Segundo, CA
Lines: 41

John McCarthy writes:
| I'm suspicious that "emergent" is just a fancy term for the fact
| that any system has some properties that are not properties of
| the components.  Let's take a trival example.  Suppose we make
| an EXOR circuit out of AND gates and inverters.  3 AND gates and
| 3 inverters will do it.  Does the fact that the circuit computes
| EXOR count as an emergent property, since none of the components
| computes EXOR?  I suspect the users of "emergent" want to suggest
| something fancier.  But what?

and Marvin Minsky writes: 
| What is fascinating is the extent to which, in science, it has so
| often sufficed merely to know the dyadic relationships of the objects,
| just two at a time.  This is the case in Newtonian mechanics; all the
| forces are simply dyadic, and one has only to sum them to find the
| accelerations that determine all the trajectories.

It seems to me that an important distinction is between designed systems,
in which the components interact in pre-specified ways, and other sorts
of interactions, which we tend to understand best if there are only two
elements interacting.  (As an aside, as a society we seem to make this a
legal distinction allowing patents on designed objects but not on laws
of nature, which tend to be binary.)

A second important distinction is between intentionally and accidently
designed systems.  I would call the "design" that is encoded in the
genetic codes of various species accidental design.  The "information"
in the genetic code certainly determines how organisms will develop and
"operate."  But the design so encoded is totally ad hoc and
"accidental."  (Sorry about all the quotes.  I can't think of better
words.)  This contrasts with designs that are encoded in software,
persumably intentionally.

My hypothesis is that we tend to think of a property as emergent if it
is a result of an accidently designed system.  So, EXOR circuits are not
normally thought of as having emergent properties since those properties
are seen as intentionally designed in.  Other properties that are not
thought of as intentionally designed into a system but that exist
because of the way the system is designed are seen as emergent.

-- Russ Abbott@itro3.aero.org