My strategy for pursuing
political, moral, and biological questions consists of three basic steps in the
following order. The first is
Platonic. I look for the idea that is
expressed in a wide range of phenomena across time and space. The second is Aristotelian. I look for the way in which the idea answers
different questions in different contexts.
The third is Darwinian. I look
for how the idea might emerge in the evolutionary history of the organisms in
which it is expressed.
Consider the wing. We recognize wings in a wide variety of
animals. In all cases, it is a
biological appendage that allows the creature to gain altitude by beating the
air. In a fundamental sense, the wing of
a bat, a bird, a pterodactyl and a dragonfly, are all the same thing. Plato (or his Socrates) would be
pleased. The wings are very different,
however, in their basic design. One has
to lift a heavy reptile; another, a creature as light as a feather. Aristotle would point this out to his
teacher. The various wings are also
examples of convergence. This is a term in Darwinian explanations that
indicates an independent evolution toward a common trait as opposed to homology, which indicates a trait shared
because it is inherited from a common ancestor.
Bats and birds don’t have wings because they inherited them from a
common ancestor, but because they worked out the same basic mechanics on their
own.
I have found this strategy to be fruitful
when applied to my primary interest, morality and politics. My work on autonomy (which I hope to be
published soon) is an example that is illustrated in previous posts. Here I apply it to reciprocity, one of the
basic foundations of cooperation in animals (including human beings). When some party X pays a cost on behalf of
some other party Y because there is a reasonable expectation that the cost will
be repaid with profit, that is
reciprocity. That this is a genuinely
Platonic idea is indicated by the abstraction of the terms. It can apply to two teams of dolphins cooperating
with one another of different days and to a fellow tipping big at a local
restaurant. Obviously the mechanisms are
different. Less obviously but very
likely, they both owe their operation to evolved dispositions.
Reciprocity is a powerful engine
for cooperation, but in its direct form (an exchange between two parties) it is
limited to specific exchanges. When we’re
done we’re done. Indirect reciprocity,
by contrast, can knit together much larger communities of cooperators. This is when an individual is influenced by
observing third party cooperation. In
such a case, the cooperator benefits by building a reputation as a good partner. The observer benefits by recognizing the
altruist as a promising partner.
Tonight I read two accounts of
indirect reciprocity. One was a study of
cleaner fish and their clients (Bshary & Grutter, “Image scoring and cooperation
in a cleaner fish mutualism”, Nature
22 June 2006). Cleaner fish feed on
ectoparasites in the mouths of much larger fish. This is a classic example of reciprocity in a
morally charged context. If the cleaner
fish eats ectoparasites, it will benefit its larger client. However, it prefers mucus, if it has a
choice. Eating mucus does not benefit
the client. So the cleaner is tempted to
cheat. In some cases, the client fish is
also tempted to cheat by eating the cleaner; however, in most cases the client
fish do not prey on other fish. So how
are cleaner fish encouraged to be honest?
The answer seems to be that
client fish pay attention. They
recognize which cleaners are good cooperators and which are not. They allow the one but not the other to
service them. The cleaners then have an
interest in appearing to be good cooperators.
They are more likely to restrain their appetites and eat only the less
preferred food (ectoparasites) when they
are observed by other potential clients.
I am pretty sure that there are
no moral theorists among Laborides
dimidaiatus. Nor do these tiny denizens
of the deep reflect on their behavior.
Their behavior is nonetheless logically
moral.
That this is an expression of a
Platonic idea is indicated by the fact that it occurs in very different
species. James R. Anderson et. al., have
found it in capuchin monkeys [Cognition 127 (2013) 140-146]. “
Here we show that capuchin monkeys discriminate between humans
who reciprocate in a social exchange with others and those who do not. Monkeys
more readily accepted food from reciprocators than non-reciprocators or partial
reciprocators.
Hitomi Chijiiwa et al found much
the same among domestic dogs [Animal
Behavior 106 (2015) 123-127].
To put it mildly, cleaner fish
and their clients, capuchin monkeys, and lapdogs occupy very diverse branches
on the tree of life. It seems likely this
is a case of convergence rather than homology.
That makes the case for Plato stronger.
The same basic idea (indirect reciprocity) is expressed independently in
a number of distinct cases. Aristotle
would remind us to pay attention to the differences. Capuchin monkeys and beagles are
psychologically social species. They
have, no doubt, a pallet of emotions that from which they paint out their
behavior. As for fish, probably not so
much. Darwinian theory helps us
understand how this Platonic idea arises in each case.
Plato and Aristotle were right,
even when they disagreed with each other.
Both of them need Darwin to complete their accounts. Aristotle understood that teeth make chewing
possible is essential to explaining what teeth are. Darwin explain how chewing explains
teeth. Plato understood that shark’s
teeth and his teeth were the same thing.
Darwin explains why Plato was right.