Newsgroups: comp.ai.philosophy
Path: cantaloupe.srv.cs.cmu.edu!das-news.harvard.edu!news2.near.net!MathWorks.Com!europa.eng.gtefsd.com!howland.reston.ans.net!cs.utexas.edu!news.unt.edu!hermes.oc.com!internet.spss.com!markrose
From: markrose@spss.com (Mark Rosenfelder)
Subject: Re: Is Common Sense Explicit or Implicit?
Message-ID: <CwEC2D.JLG@spss.com>
Sender: news@spss.com
Organization: SPSS Inc
References: <35hhm3$k74@mp.cs.niu.edu> <35ibd4$aup@newsbf01.news.aol.com>
Date: Mon, 19 Sep 1994 21:37:24 GMT
Lines: 74

In article <35ibd4$aup@newsbf01.news.aol.com>,
DrewDalupa <drewdalupa@aol.com> wrote:
>In article <35hhm3$k74@mp.cs.niu.edu>, rickert@cs.niu.edu (Neil Rickert)
>writes:
>>>No language, no awareness of repetition, no awareness that two
>>>things are the same.
>
>>By your own example, this would imply that the bird has language.
>
>Not merely because it recognizes its mate!  It *would* have
>to have language on my theory if, aside from recognizing its
>mate, it remembered *that* this was the same bird as the
>one it had "married".  Let it put it this way:  the bird is faithful,
>but not because it remembers a vow made in a church.  Not
>because it remembers any past event.  Recognizing an individual
>is not in principle different from recognizing two people who
>look the same.  At first, I could tell apart Ernest/Jerry from
>anybody else, but not Ernest from Jerry.  By the same
>token, a cricket can tell apart female from male, but not
>necessarily male from male or female from female.  Nevertheless,
>I knew *that* Ernest and Jerry were not the same person, only
>I had to keep asking.  My question is, does the bird have any
>opinion on the matter of whether the other bird is one bird or
>a succession of identical birds?  Maybe the bird does have an
>opinion, but if so, I think it would be *very* interesting to
>see how it manages this.  I am ready to dump my idea if I can
>get some specific account of this.

First off, just to provide some biological background, it seems pretty clear 
that birds can recognize individuals of their species-- that is, they do not 
distinguish "mate" from "non-mate", but "know" the individual birds in their 
flock-- Polly, Biff, Scooter, etc.  See Konrad Lorenz's accounts of jackdaw
and greylag goose behavior.

All these problems are ones of categorization, in my opinion.  We (and 
the birds) have a remarkable ability to classify very different sensory
perceptions as instances of a single category ("human", "maple", "cat", etc.).
The problem of recognizing an individual is really the same problem--
recognizing that Polly seen in the morning and the evening, or seen in
profile or full face, or from the front or back, or flying or walking,
are all instances of a single category "Polly".

Now, birds seem to be able to recognize both classes of objects (e.g.
species of prey; species of predators; types of suitable nesting materials)
and individuals.  Your question amounts to asking if they can tell 
the difference between a class and an individual.

One possible answer is that they can't because they don't need to.
We can ask such a question because of our language ability; without it
we could neither ask nor answer it.

Another approach is to ask if the difference could be exploited implicitly
by the bird: can it *act* as if it can tell an individual from a class?
For instance, one difference between an individual and a class is that
you never see more than one instance of an individual.  If the bird knows
that its mate is home with the nestlings, then it could deduce that it
cannot also be feeding on the lawn.  I suspect that birds do understand
this (if a bird goes looking for its mate, upon finding it it doesn't
keep looking in hopes of finding another one), but it would be hard to
rule out other explanations.

>In any case, I would like to know in what sense specific past
>events are remembered by animals, and why one has to
>suppose this capacity to recollect.

It seems pretty clear that animals have object permanence (they know how
to get home, they recognize old friends --and enemies), which is arguably
a form of remembering the past.  And they can associate a particular
location or action with a good or bad event that occurred there.  
I'm not sure how you'd prove that they do or do not remember an event
in the same way we do, however.

I'm reminded of someone's sig file-- "The ancient Egyptians worshipped 
cats as gods.  Cats have never forgotten this."
