Species as Individuals in the Hierarchical Theory of Selection 629
complex nature to meet your theoretical needs, but then claim that you will
simplify the actual circumstances "as if" the system under study operated in the
required way. The classical "as if" argument goes by its Latin title of ceteris
paribus, or "all other things being equal." Ceteris paribus imposes additivity upon
a system truly made of complexly interacting parts. You isolate one factor and
state that you will analyze its independent effects by holding all other factors
constant.
Ceteris paribus ranks among the oldest of scholarly devices, an indispensable
tactic for any student of complex systems. I am certainly not trying to mount a
general assault upon this venerable and valuable mode of exemplification. Two
common circumstances define the legitimate domain of ceteris paribus: (1) as a
heuristic or exploratory device for approaching systems of such complexity that
you don't even know how to think about influences of particular parts, unless you
can hypothetically assign all others to a theoretical background of constancy; and
(2) as a powerful experimental tool when you can actually hold other factors
constant and perturb the system by varying your studied factor alone.
But ceteris paribus becomes an illegitimate dodge, an invalid prop to make a
potentially false argument unbeatable by definition, in systems dominated by
nonadditivity—that is, where the very act of holding all other factors constant may
make your favored factor work in a manner contrary to its actual operation in a real
world of interaction. If A conquers B only when the two entities share a field
alone, but usually loses to B when C also dwells on the field, and if real fields
invariably include C, then we cannot crown A as absolutely superior to B on the
basis of a single and artificial ceteris paribus trial that excluded C from action and
consideration.
The use of ceteris paribus to support gene selectionism constitutes a similar
denial of a known reality. This tactic represents a fallback position after
acknowledging the impossibility of asserting a genuine claim for nonadditivity in
the translation of genes to organisms. In other words, you admit that massive
nonlinearity actually exists, but then state that, for purposes of discussion, you will
counterfactually impose ceteris paribus so that genes can be equated with linear
effects. For example, Dawkins explicitly invokes the key phrase (in English rather
than Latin) in defending his requisite (but fallacious) notion that genes may be
identified as operating "for" particular parts of phenotypes, thus creating the
impression that organisms may be treated as additive aggregates rather than entities
defined by nonlinear interaction.
For purposes of argument it will be necessary to speculate about genes
"for" doing all sorts of improbable things. If I speak, for example, of a
hypothetical gene "for saving companions from drowning," and you find
such a concept incredible,... recall that we are not talking about the gene
as the sole antecedent cause of all the complex muscular contractions,
sensory integrations, and even conscious decisions, which are involved in
saving somebody from drowning. We are saying nothing