Knowledge and Selection:
The Two Approaches to Evolutionary Epistemology
Wei-Li Jao
Ph.D. Candidate in Philosophy
Graduate School and University Center
City University of New York
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I.
Introduction
Evolutionary epistemology aims to enrich our understanding of knowledge by
incorporating the perspective of evolutionary theory into the study of epistemology.
Among its most eminent advocates in philosophy are Quine and Popper. Quine
believes that the reliability of human cognitive system has its root in natural selection.
For instance, in relation to the issue of induction, Quine says that
Why does our innate subjective spacing of qualities accord so well with the
functionally relevant groupings in nature as to make our induction tend to come
out right? ... There is some encouragement in Darwin. If people’s innate spacing
of qualities is a gene-linked trait, then the spacing that has made for the most
successful induction will have tended to predominate through natural selection.
Creatures inveterately wrong in their inductions have a pathetic but praiseworthy
tendency to die before reproducing their kind. (Quine 1969, 126)
And Popper thinks that the development of human knowledge is driven by a cultural
transmission process that is analogous to natural selection that governs biological
evolution. Popper claims that
The growth of our knowledge is the result of a process closely resembling what
Darwin called ‘natural selection’ … our knowledge consists, at every moment, of
those hypotheses that have shown their (comparative) fitness by surviving so far
in their struggle for existence; a competitive struggle which eliminates the
hypotheses that are unfit. (Popper 1972, 261)
Quine and Popper’s views represent the two approaches to evolutionary epistemology.
Theses two approaches attempt to lend support from one of the core theses of
evolutionary theory—the theory of natural selection—to either explains the reliability
of human cognitive system or the growth of human knowledge. Both approaches have
been accused of abusing the theory of natural selection. In particular, the Quinean
approach is often being criticized on the basis that it commits the fallacy of
adaptationism and the Popperian approach is usually opposed on the ground that no
appropriate analogy is available between biological evolution and cultural
transmission.
It is the goal of the present paper to resolve these objections to evolutionary
epistemology. To achieve this goal, the dispositional feature of natural selection will
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be investigated, the schematic characteristic of the theory of nature selection will be
explored, and the relation between evolutionary epistemology and the objectivity of
knowledge will be discussed.
II.
The Quinean Approach and Adaptationism
Central to the Quinean approach to evolutionary epistemology is the thesis that human
cognition system is a biological adaptation by natural selection for the function of
producing truthful mental representation1. What is noteworthy about this thesis is its
explicit commitment to adaptationism. Adaptationism is a research program in
contemporary evolutionary theory that emphasizes, in one way or another, the role
that natural selection plays in biological evolution. This research program has been
inciting some of the most intense debates in contemporary evolutionary theory and
some versions of adaptationism have been rejected by all parties joining the debates.
The critics of evolutionary epistemology often take this fact as implying the
bankruptcy of the Quinean approach. Yet it is far from clear that the type of
adaptationism to which the Quinean approach subscribes could also be subject to the
same arguments against those false versions of adaptationism. A close inspection on
the source of the controversies surrounding adaptationism is needed for deciding the
truth of the Quinean approach.
Contemporary evolutionary theory contains two important theses that were first put
together by Darwin in On the Origin of Species in 1859. According to the first thesis,
all species are derived from a common ancestor through a series of alteration (descent
by modification); and according to the second thesis, this alternation is accomplished
by means of natural selection (evolution by natural selection). Darwin believed that
the question of speciation—i.e., how do new specie arises from old species?—could
be fully explained in terms of these two theses. The current consensus is that Darwin
did not succeed in providing a complete account of speciation because he had failed to
see that speciation could also be achieved by evolutionary processes other than natural
selection. Yet this does not in any way undermine the significance of Darwin’s two
theses in contemporary evolutionary theory. People who work in evolutionary biology
or related disciplines generally agree that these two theses are indispensable for
explaining some of the most striking features in the biological world. For example, it
1
The majority of evolutionary thinkers adopt a historical notion of adaptation, according to which an
adaptation is a trait evolved by natural selection. On this notion of adaptation, a trait might be an
adaptation without being currently adaptive and vice versa. Gould and Vrba (1982) coin the term
“exaptation” for currently adaptive but non-selected traits to distinguish them from adaptations.
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is unanimously recognized that the diversity of life on earth—the variety of
organismic forms—is intelligible only in relation to the series of alteration depicted in
the thesis of decent by modification. More importantly, it is also widely
acknowledged that at least some part of the design-like feature in nature—the design
exhibited by complex biological traits—is comprehensible only with reference to the
evolutionary process illustrated in the thesis of evolution by natural selection. The
conviction that natural selection is capable of giving rise to design-like complex trait
is the fundamental motivation for adaptationism.
Evolutionary thinkers have been seeking to clarify the structure of the theory of
natural selection. Lewontin (1970), for example, characterizes the theory of natural
selection as a schema consisted of the following three principles: principle of
variation, heritability, and fitness, which states respectively that natural selection
requires there be phenotypic variation among members of a population, that natural
selection requires the variation be heritable, and that natural selection requires the
variation be correlated with the differential reproduction between members of a
population. Lewontin notes that there is a certain generality in this schema, for no
particular mechanism of phenotypic variation, inheritance, or reproduction is
specified in those principles. The consequence of this generality is that ‘any entities in
nature that have variation, reproduction, and heritability may evolve…the principles
[of natural selection] can be applied equally to genes, organisms, populations, species,
and at opposite ends of the scale, prebiotic molecules and ecosystems’ (Lewontin
1970, 1-2). Natural selection, understood this way, is more a universal mechanism for
evolutionary change at all levels of biological hierarchy than something only for
organismic evolution as it is often thought. Sober (1993) summarizes Lewontin’s
three principles as “heritable variation in fitness” and claims that they are necessary
for natural selection.
Brandon (1990) points out that the theory of natural selection calls for a stronger
version of principle of fitness than the one proposed by Lewontin. As it stands,
Lewontin’s principle of fitness allows the correlation between phenotypic variation
and differential reproduction be obtained by chance along. To fix this defect, Brandon
suggests that the correlation between phenotypic variation and different reproduction
stated in the principle of fitness must be the result of interaction between biological
entities and their environments, so as to make the reproductive success of biological
entities positively associate with the adaptedness of these entities to their
environments. Expressing Brandon’s idea in Sober’s terminology, one can say that
natural selection is not just any kind of heritable variation in fitness, but the
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non-random sort of heritable variation in fitness due to environmental interaction.
While a formulation of the theory of natural selection similar to the one outlined
above is adopted broadly among evolutionary thinkers, there is no general consensus
as to the place that the theory of natural selection occupies in contemporary
evolutionary theory. In particular, evolutionary thinkers maintain a wide spectrum of
attitudes toward the issue of how many and what design-like traits in nature should be
accounted for in terms of natural selection. This disagreement has to do with the
observation that natural selection is but one of many processes capable of giving rise
to evolutionary changes. According to contemporary evolutionary theory, biological
evolution is driven by a variety of processes, which can be suitably divided into two
groups: selection processes such as natural selection and non-selection processes such
as genetic drift2. Natural selection and genetic drift are not mutually exclusive, as both
can and often operate side by side in the same evolutionary episode of a population.
Both natural selection and genetic drift are believed to be able to give rise to
design-like traits. Natural selection is thus not the only process responsible for this
prevalent biological phenomenon and therefore might not be the only factor figured in
its explanation.
Nonetheless, natural selection and genetic drift differ from one another sharply on the
sorts of evolutionary changes they are capable of bringing about. Evolutionary
biologists and population geneticists often define genetic drift as the random
fluctuation in the gene frequency in a population due to sampling error3. Understood
this way, genetic drift is essentially a random process which leads to nothing but
haphazard events in biological evolution. Natural selection, on the other hand, is
disposed to facilitate the fit between organisms and their environments in such a way
as to enhance the likelihood of emergence of design-like traits. To be sure, genetic
drift might also be able to produce such fit and yield designed-like traits in some cases,
but owing to its lacking of the corresponding disposition it could achieve this only in
a fortuitous way. In other words, both natural selection and random drift are capable
of giving rise to the fit between organisms and environments necessary for the
existence of design-like traits, but their capabilities in generating such fit are of two
distinct types: the ability of natural selection is a dispositional one which works
toward increasing such fit, whereas the ability of random drift is a non-dispositional
2
Sexual selection and mutation are also known to be able to produce evolutionary change. The former
is normally categorized as a selection process and the latter a non-selection process. Much of the
contrast between natural selection and genetic drift discussed in this paper also applies to selection and
non-selection processes in general, including sexual selection and mutation. It will be noted when this
is not the case.
3
See Hartl and Clark (1989) and Futuyma (1998) for similar definitions of genetic drift.
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and random one which works toward no definitive direction.
Natural selection implements this disposition by preserving traits of higher adaptive
value and eliminating traits of lower adaptive value in a population. A trait x is more
adaptive than another trait y in a population living in a common environment if x is
fitter than y in the population, for being able to better assist its possessors cope with
issues of survival and reproduction than y to its possessors in the population, in terms
of the average reproduction success rates (or ‘fitness’ in short) of x and y possessors in
the population. Thus, for a population of organisms, organisms with traits of higher
adaptive value are inclined to leave more offspring than those with traits of lower
adaptive value. When the traits in question are heritable, the proportions of organisms
with traits of higher adaptive value and organisms with traits of lower adaptive value
in the population would tend to increase and decrease respectively over generations;
consequently, the relative frequencies of traits of higher adaptive value and traits of
lower adaptive value would fluctuate in a corresponding manner. Provided that no
population could grow indefinitely, organisms with traits of lower adaptive value in
the population would then tend to be gradually replaced by organisms with traits of
higher adaptive value in the same population.
Following such systematic
replacement of less adaptive organisms with more adaptive organisms is the steady
increasing in the fit between the average member of the population and its
environment would be steadily enhanced, which would in turn lead to increasingly
complex traits that exhibit design-like features, given that evermore adaptive traits
keep arising and natural selection never ceases to operate in the population, ceteris
paribus.
That natural selection is disposed to facilitate the fit between organisms and
environments in a manner resulting in progressively complex design-like traits leads
adaptationists to stress the importance of natural selection in biological evolution.
Natural selection occupies a unique place in the evolution of design-like traits because
these traits are often too complex to be evolved by random evolutionary processes
such as genetic drift. A complex design-like trait is usually consisted of a number of
components which are no less complicated in themselves than the trait they compose;
and these components are often in turn made of a number of sub-components and so
on and on. For such a trait to come into existence and maintain its operation as a
cohesive whole, all of its components and sub-components must enter into a massive
causal network in which these components interact with one another. It appears very
unlikely that each of every single component of such a trait would fall right in its
proper place in such a causal network purely by chance in the evolution of the trait. A
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non-random evolutionary process with a certain disposition such as natural selection
is thereby essential to the explanation of the evolution of complex design-like traits.
The Quinean approach to evolutionary epistemology hinges on the adaptationist idea
that human cognitive system is a biological adaptation evolved by natural selection
for the function of producing truthful mental representation. Given the reliability and
complexity of human cognitive system, it is quite implausible that human cognitive
system could have evolved by means other than natural selection. It appears that
truthful mental representations tend to make organisms be better at monitoring,
coordinating with, and thus adapting to their environments, whereas untruthful mental
representations tend to have just the reversed effects. Truth and adaptiveness are
hence connected in such a way so as to render the reliability of human cognitive
system under the examination of natural selection.
One popular line of objection to the Quinean approach to evolutionary epistemology,
exemplified in Stich (1990), is to argue for the possibility that human cognitive
system might have been brought about by means other than natural selection.
According to Stich’s analysis, the argument implicit in the Quine approach involves
the following pair of premises:
(a) that “evolution produces organism with good approximation to optimally
well-designed characteristics and systems”,
(b) that “an optimally well-designed cognitive system is a rational cognitive system”
(Stich 1990, 56),
where an optimally well-designed system is a system that “enhances biological fitness
more than any alternative” (Stich 1990, 57) and a rational cognitive system is a
reliable cognitive system that “generally produces true beliefs” (Stich 1990, 58).
Stich notes that each of these two premises has a certain prima facie plausibility, but
he doubts that any of them can pass further scrutiny. With respect to the first premise,
Stich argues that it is undercut by the following four considerations:
(1) Natural selection is only one of the various processes for evolution change. Other
evolutionary processes such as genetic drift might lead to the elimination of the
fittest traits and the fixation of the less fit traits.
(2) Natural selection is constrained by the phenotypic variation available in a
population. The fittest traits might have never had the opportunity to appear in
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the population to be selected by natural selection.
(3) Natural selection is constrained by the structure of a population as well. Some
population structures might prevent the fittest trait to be selected by natural
selection.
(4) Non-biological factors such as cultural factors might also play an important role
in the evolution of human cognitive system such that human cognitive system
might not be optimal even though natural selection is an inveterate optimizer4.
And with regard to the second premise, Stich contends that it is mistaken for the
following two rationales:
(1) A reliable cognitive system might be less fitness-enhancing than a less reliable
one because the former might be more costly and less efficient than the latter.
(2) A reliable cognitive system might be less fitness-enhancing than a less reliable
one because true beliefs might not be more fitness-enhancing than false beliefs.
The Quinean approach to evolutionary epistemology stands firm in the face of Stich’s
arguments, for the adaptationism to which the Quinean approach commits does not
assert that natural selection guarantees or insures the emergence and maintenance of
reliable human cognitive system. What is asserted is a somewhat weaker thesis that
natural selection is the most plausible processes that could have brought about human
cognitive system given the degree of reliability and complexity of human cognitive
system. Granted that natural selection is constantly restrained by other aspects of
biological evolution for its operation and effect, it is still more reasonable to expect
that human cognitive system was evolved by natural selection, considering its
sophisticated design-like features. Stich’s arguments against the Quinean approach are
mistaken because they are not sensitive to the dispositional nature of the selection
explanation embedded in the Quinean argument; it is certainly possible that human
cognitive system was evolved by means other than natural selection, yet nothing is
more probable than natural selection to have brought about such a reliable cognitive
system. If one were to construe the Quinean approach in Stich’s terminology, the more
plausible premises for this approach out to be the ones expressed in the following two
statements:
(a') It is more probable for organisms with good approximation to optimally
well-designed characteristics and systems to be evolved by natural selection than
4
The influence of culture on the evolution of human cognitive system will be considered in the last
section of this paper.
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by any other means.
(b') It is more probable for an optimally well-designed cognitive system to be a
rational cognitive system than a non-rational one.
Another line of objection to the Quinean approach to evolutionary epistemology,
represented by Plantinga (1993), is to argue for the improbability that natural
selection could have given rise to human cognitive system. Plantinga claims that on
the assumptions that (R) human cognitive system is reliable, that (C) human beings
have the cognitive faculties that they have, that (E) these faculties have been produced
by evolution, and that the probability of R given N&E&C—P(R/(N&E&C))—is fairly
low, where N is naturalism, one could construe “a straightforward probabilistic
argument against naturalism—and for traditional theism” (Plantinga 1993, 228),
which would in turn undermine contemporary evolutionary theory along with all other
theories based on naturalism. Plantinga builds his case on Bayes’ Theorem, according
to which
P(( N & E & C ) / R ) 
P( N & E & C )  P( R /( N & E & C ))
P( R )
where P(N&E&C) is the unconditional probability for N&E&C estimated
independent of R. By supposition P(R) is near 1 and P(R/(N&E&C)) is no more than
1/2. Then P((N&E&C)/R) will be no greater than 1/2 times P(N&E&C), and will
thereby be fairly low. Since by supposition both P(C) and P(E) are also near 1, so
P(N/R) will be fairly low too. But P(R) is near 1, R will therefore be the evidence
against N. In other words, the belief that “[human] cognitive faculties are reliable
gives a reason for rejecting naturalism and accepting its denial” (Plantinga 1993, 228).
Based on this Bayesian argument, Plantinga argues further that N&E—the
conjunction of naturalism and evolutionary theory—is self-defeating for it “provides
for itself an undefeated defeater” (Plantinga 1993, 235).
Indispensable to Plantinga’ Bayesian argument is the assumption that P(R/(N&E&C))
is pretty low. In motivating this claim, Plantinga argues that unreliable cognitive
system might have evolved by natural selection for the following reasons:
(1) Beliefs might not be causally efficacious, causally efficacious in virtue of their
content, or causally connected with behaviors, such that the
reliability/unreliability of cognitive system might not have any effect on the
fitness of organisms.
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(2) The genetic codes code for unreliable cognitive system might also code from
some fitness-enhancing traits, such that the harmful effects of unreliable
cognitive system might be outweighed by the benefiting effects of these
fitness-enhancing traits.
(3) The desire system might compensate unreliable cognitive system, such that pairs
of false-belief/offsetting-desire might be adaptive.
(4) The part of cognitive system responsible for producing theories about matters
irrelevant to survival and reproduction of organisms might not be adaptive5.
Plantinga claims that the possibilities stated above are mutually exclusive and jointly
exhaustive. If this is so, then the probability of R, of human cognitive system’s being
reliable, would equal to the weighted average of the probabilities for R on each of
these possibilities. Since the probability for R on each of the three possibilities stated
in (1) is no more than 1/2, it is reasonable to expect that the probability of R would be
relatively low, somewhat less than 1/2. Therefore, P(R/(N&E&C)) would be lower
than its denial too, Plantinga concludes.
Plantinga’s argument for the low probability of R on N&E&C falls apart when one
reflects on the probability that human cognitive system, being as reliable and complex
as it is, might have come into existence by means other than natural selection. It
appears quite implausible that human cognitive system could have evolved by
non-selection evolutionary processes, considering the randomness of these processes.
Instead, it might be the case that human cognitive system is the creation of God, as
Plantinga would like to argue. However, there is no independent evidence for
believing this possibility. An argument of Plantinga’s sort is not capable of providing
such evidence, for such an argument presupposes that P(R/(N&E&C)) is fairly low to
prove the truth of theism. It would then be circular if one appeals to the possibility of
human cognitive system’s being created by a deity to show that P(R/(N&E&C)) is
fairly low, because that P(R/(N&E&C)) is fairly low is but one prerequisite for
Plantinga’s Bayesian argument for theism. The probability that human cognitive
system have come into existence for reasons other than natural selection is thereby
relatively small.
Both Stich and Plantinga attempt to dismiss the Quinean approach to evolutionary
epistemology by cutting short the conceptual tie between truth and adaptiveness. But
their strategy is ineffective, as the Quinean argument for the reliability of human
cognitive system makes no use of such a conceptual relation. The conceptual gap
5
This question will be considered in the last section of this paper.
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between truth and adaptiveness—that truth does not guarantee adaptiveness and that
adaptiveness does not require truth—is not something objectionable from the
perspective of the Quinean approach, for it too recognizes the fact that there is
nothing necessary about natural selection. However, that truth and adaptiveness are
not bound up together in an a priori manner does not imply that neither could they be
connected in an a posteriori fashion. Truth and adaptiveness might be associated
together by natural selection, non-selection evolutionary processes, or even a deity.
What the Quinean approach shows is that, given the reliability and complexity of
human cognitive system, natural selection is the most plausible means by which
human cognitive system could have been brought about into existence. In other words,
the Quinean approach demonstrates that the reliability of human cognitive system
could be best explained in terms of the disposition of natural selection. To refute the
Quinean approach, the critics of evolutionary epistemology must come up with an
explanation for the reliability of human cognitive system that does a better job than
the one that the Quinean approach devises based on the theory of natural selection.
Before such an explanation is found, the Quinean approach to evolutionary
epistemology remains sound and viable.
III. The Popperian Approach and the Doctrine of Cultural Transmission
Essential to the Popperian approach to evolutionary epistemology is the doctrine of
cultural transmission which states that conceptual change in cultural evolution can be
modeled in terms of the theory of natural selection. The advocates of the Popperian
approach believe that such a doctrine can be drawn from the schematic nature of the
theory of natural selection. It appears that the constituent principles of the theory of
natural selection can all be defined in a topic-neutral way without specifying their
subject matter. Many evolutionary thinkers have taken notice of the topic-neutrality of
these principles and set out to build on them a general account of selection. Their
endeavor has occupied a vital role not only in explicating the theory of natural
selection but also in vindicating the natural/cultural analogy required for the
Popperian approach to evolutionary epistemology.
As mentioned, Lewontin construes the theory of natural selection as a schema
consisted of the principles of variation, heritability, and fitness, which can be applied
to account for cases of selection across different levels of biological hierarchy. Like
Lewontin, Dawkins also notices the generality in the explanatory pattern of the theory
of natural selection. However, Dawkins is even more ambitious in exploring the
implication of the topic-neutrality of the principles of which the theory of natural
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selection is constituted.
Being one of the most eloquent proponents of gene selectionism, Dawkins has long
been known for his claim that gene is the unit of selection. For Dawkins, a unit of
selection must be an entity capable of replicating itself with certain accuracy in
evolutionary processes. Dawkins coins the term “replicator” for this sort of entities, in
contrast to “vehicle” that “houses a collection of replicators and which works as a unit
for the preservation and propagation of those replicators” (Dawkins 1982, 114). He
argues that nothing else in the biological world on earth but genes are capable of
making copies of themselves; organisms, populations, species, higher taxa and
ecosystems do not copy themselves as genes do. Genes are therefore special because
they are replicators which propagate for their own sake, whereas organisms and other
biological entities are merely the vehicles that genes build and ride in, according to
Dawkins. On this view of biological evolution, even we are created by our genes and
“their preservation is the ultimate rational for our existence” (Dawkins 1976, 20).
Dawkins formulates the replicator/vehicle distinction not only to explicate the gene
selectionism initially outlined by G. C. Williams (1966), but also to motivate the
universal Darwinism that he develops from it. Dawkins takes genes to be the only sort
of replicators that participate in the biological evolution on this planet, but he
maintains that this needs not be the case for biological evolution in general. This is
because, on Dawkins’ replicator notion, anything could be a replicator insofar as it is
able to make faithful copies of itself, regardless of what it is physically made of. If
there were other life forms in other parts of the universe, then the replicators involved
in the evolution of these life forms might not be genes as we know them. But we do
not need to travel far to seek non-gene replicators, as a relatively new sort of
replicators can be readily found in the cultural transmissions that have been occurring
on earth for the past few million years. These replicators are cultural entities which
spread themselves from brain to brain by means of imitation, in a manner similar to
genes’ propagating themselves from body to body by means of genetics. Examples of
these cultural replicators include “tunes, ideas, catch-phrases, clothes fashions, ways
of making pots or of building arches” (Dawkins 1976, 192). Dawkins coins the term
“meme” for this kind of replicators, of which Dawkins professes that it “seems to be
turning out to be a good meme” itself (Dawkins 1976, 322). Given that memes are
genuine replicators, Dawkins concludes that cultural transmission can be suitably
understood as a process governed by cultural selection analogous to natural selection
that regulates biological evolution. Dawkins’ meme concept has been further
developed by Dennett (1995) and Blackmore (1999), who are to a great extent
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responsible for the rising of a new discipline in the study of culture called
“memetics”.
The meme concept adopted by the majority of memeticists does not fit well with need
of the Popperian approach to evolutionary epistemology. For the most of time,
memeticists bases the meme concept on Dawkins’ gene’s eye view of biological
evolution, which takes genes to be the selfish replicators that propagate for their own
shake with no regard to the welfare of their vehicles. Memes, as genuine replicators,
are said to have the same superior authority to their vehicles as genes to theirs, such
that memes too will get themselves copied whenever they can even at the cost of their
subordinates. Dennett describes this feature of memes as “the first rule of memes”
(Dennett 1995, 362) and Blackmore calls this view of cultural evolution “the meme’s
eye view” (Blackmore 1999, 8). One implication of the meme’s eye view is that
memes do not need to be true to get themselves copied; a false but provocative belief
could spread more easily and widely than a true yet dull one. The Popperian approach
will then not be able to address issues concerning the advancement of knowledge if
the meme’s eye view is the only doctrine of cultural transmission available to it.
Dawkins’ the other two concepts—replicator and vehicle—have also attracted a great
deal of criticisms for their close association with the gene’s eye view of biological
evolution. For instance, the replicator concept is often being criticized on the basis
that nothing, including genes, is capable of making copy of itself in a literal sense 6,
and the vehicle concept is undermined by its provoking connotation that vehicles such
as organisms are nothing but “lumbering robots” programmed and controlled by
replicators for their selfish propagation.
One way that the advocates of the Popperian approach can get around these criticisms
is to detach the doctrine of cultural transmission from gene selectionism. This is
exactly what Hull sets out to do. Like Lewontin and Dawkins, Hull is also impressed
by the schematic nature of the theory of natural selection. He proposes to capture the
generality in the explanatory pattern of the theory of natural selection by revising
Dawkins’ replicator concept and replacing Dawkins’ vehicle concept with his own
interactor concept. According to Hull, a replicator is “an entity that passes on its
structure largely intact in successive replications” and an interactor is “an entity that
interacts as a cohesive whole with its environment in such a way that this interaction
Lewontin, for instance, claims that genes “cannot make themselves any more than they can make a
protein. Genes are made by a complex machinery of proteins that uses the genes as model for more
genes. When we refer to genes as self-replicating, we endow them with a mysterious, autonomous
power that seems to place them above the ordinary materials of the body” (Lewontin 1991, 48).
6
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causes replication to be differential” (Hull 1988, 408). Selection therefore can be
defined as “a process in which the differential extinction and proliferation of
interactors cause the differential perpetuation of the relevant replicators” (Hull 1988,
409). According to Hull, candidates for replicators range from genes, genomes,
organisms to perhaps gene pools, and interactors can be found at an even wider span
of biological hierarchy, from genes, cells, organs, organisms, colonies to possibly
entire species (Hull 1988, 428). An important implication of replication and
interaction occurring at a variety of levels of biological hierarchy is that the level at
which natural selection occurs also wanders from level to level. The resulting account
of selection is thus a fairly liberal one, which covers not only cases of natural
selection at multiple levels of biological organization, but also cases of somatic
selection in immune system, operant selection in behavior (Hull et al. 2001), and most
importantly, conceptual selection in culture in general and in science in particular
(Hull 1988).
Hull describes conceptual replication in general as “a matter of ideas giving rise to
ideas via physical vehicles, some of which also functions as interactors” and the
conceptual selection in science as a special case of conceptual replication in which
“replicators are generated, recombined, tested by scientists interacting with the
relevant portion of the natural world” (Hull 1988, 436). For Hull, the replicators in
scientific change are elements of the substantive content of science, such as “beliefs
about the goals of science, proper ways to go about realizing these goals, problems
and their possible solutions, modes of representation, accumulated data, and so on”
(Hull 1988, 434). Scientists are the primary interactors in this replication, because
they are “the ones who notice problems, think up possible solutions, and attempt to
test them” (Hull 1988, 434). However, Hull emphasizes that for the most of time
scientists do not play the role of interactor as isolated researchers but as members of
scientific communities. The significance of modern scientific communities in the
conceptual selection in science is manifested in the ways that they influence the
behaviors of individual scientists. Modern scientific communities are structured in
such a way so as to require scientists cooperate with their conceptual kin in promoting
their collective goal—i.e., propagating their shared beliefs. Moreover, modern
scientific communities are so organized that the personal career interests of individual
scientists are coincided often enough with the academic interest of scientific
communities—that is, the pursuit of knowledge. The image of science arisen from
Hull’s theory of conceptual selection is thus one in which individual scientists work
toward increasing their cultural inclusive fitness by confronting the natural world in
accordance with the epistemic norms set up by the scientific communities of which
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these scientists are the essential constituents.
The Popperian approach to evolutionary epistemology depends on the natural/cultural
selection analogy to model the growth of knowledge. Hull’s liberal account of
selection appears to be able to supply such an analogy. However, the critics of
evolutionary epistemology might still not be satisfied, for supposedly there is a good
deal of dissimilarity between biological evolution and cultural transmission that is left
out by the natural/cultural selection analogy. Hull, as well as Dawkins and other
memeticists, often try to set aside this type of criticism by either insisting on the
aptness of the analogy or explaining away the disanalogy. For instance, the critics of
evolutionary epistemology has pointed out that science, at least in some limited areas,
is progressive, while the progressive character of biological evolution is not nearly so
clear. In responding to this challenge, Hull argues that evolution by natural selection
is no less locally progressive than science, in that whenever natural selection occurs it
tends to increase particular population’ adaptability to particular environments, just
like science exhibits local improvements in particular episodes of its development.
However, Hull admits that biological evolution and scientific change are not entirely
alike in terms of progress, as he acknowledges that the advancement that science has
been making is more a global one than merely a local one whereas no similar sort of
progress can be found in biological evolution. But for Hull this difference is not a
serious threat that would overshadow the natural/cultural selection analogy. In Hull’s
opinion, that science is globally progressive is largely due to the fact that there are
eternal and immutable regularities out there in nature. The corresponding sort of
regularities is however absent from the biological world, because the environments to
which organisms must adapt never stop changing. Any progressive trend brought
about by natural selection toward higher adaptability in particular lineages could thus
be reversed anytime and the global pattern of biological evolution therefore keeps
fluctuating without displaying consistent progressive or regressive trajectory (Hull
1988, 476).
Yet, it does not seem that the resistance to the natural/cultural selection analogy could
be entirely neutralized this way. The usefulness of analogy comes with a costly price.
It appears that for any analogy there are countless corresponding dis-analogies that
could be readily found. Consequently, no argument based on analogy could
completely shun its criticisms rested on the relevant dis-analogies. The critics of the
Popperian approach could hence concede that biological evolution and conceptual
transmission are indeed similar in some ways without losing much of their ground. In
the absence of something better than analogy to expound the similarity between
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biological evolution and cultural transmission, it is always open to the critics to
dismiss this parallel as something illusory.
A better way to defend the natural/cultural selection analogy is to look for the
underlying reason or mechanism that leads to this analogy. Perhaps that biological
evolution and cultural transmission appears strikingly akin to each other is not just
because they are driven by natural/cultural selection processes that are similar in an
analogical sense, but because these selection processes are instances of an abstract
explanatory schema that governs all possible cases of selection. On this view of the
natural/cultural selection analogy, cultural selection is not an analogue of natural
selection, as both natural selection and cultural selection are the implementations of
the same explanatory schema of selection. Furthermore, since the realization of this
selection schema in different cases of selection might depend on different sets of
background conditions—e.g., conditions concerning the physical substrates of the
entities in theses cases of selection—it is reasonable to expect there be some
discrepancies between the realized selection processes. For the Popperian approach to
evolutionary epistemology, the benefit of endorsing such a general explanatory
schema of selection is therefore twofold: the analogical nature of the natural/cultural
selection can be explained in terms of a deeper source and the dissimilarities between
biological evolution and cultural transmission that the natural/cultural selection leaves
out can also be accounted for by the very same source7.
IV. Evolutionary Epistemology and the Objectivity of Knowledge
In responding to logical empiricists’ somewhat idealistic picture of science, Kuhn
(1962) argues that decisions between theories in scientific paradigm shifts are not
more rational than decisions between ideologies in political revolutions because of the
influence of social factors. Kuhn’s claim is often interpreted as denying the possibility
of objective knowledge. This interpretation presupposes that social factors by their
very nature are destructive to the most important means for acquiring
knowledge—science. Nevertheless, assumptions like this do not seem very appealing.
First of all, it is not clear to what extend social factors might jeopardize the epistemic
activities in science. Furthermore, some social factors might be such that not only do
7
To be sure, Hull sometimes mentions the similar point with regard to the nature of the natural/cultural
selection analogy, but only in passing and often without forgetting returning to the analogical
characteristic of that analogy. This seems to be an unnecessary mix-up of the two views of cultural
selection—the view of cultural selection as a realization of an abstract explanatory schema and that of
cultural selection as an analogue of natural selection. Occasionally, other proponents of memetics also
speak of meme not as an analogue of gene but as a genuine instance of replicator. Nonetheless, this
important point is frequently obscured by their taking gene as the unique model for replicator.
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they not endanger the ideals of science but also assist the realization of the goals of
science. An important aspect of modern scientific communities disclosed by Hull’s
account of conceptual selection is that modern scientific communities are usually
organized in such a way as to make sure that those who contribute to the advancement
of human knowledge would be properly rewarded and those who undermine the ideals
of science would be suitably penalized. This aspect of science is as non-rational as
other social factors in science, yet supposedly it is hardly injurious to science.
Moreover, the yearning for being acclaimed and the passion for truth are all factors
that play an important role in promoting the progress of human knowledge, but they
are entirely non-rational and even sometimes irrational. Thus, granted that the
epistemic activities in science are very much under the influence of a variety of social
factors, it remains as an open question as to how the objectivity of knowledge might
be affected by these so called ‘external’ factors of science.
One aspect of human knowledge that evolutionary epistemology seeks to explain is
the reliability of human cognitive system. Emerged from decades of empirical
researches in cognitive science is a picture of cognition in which human cognitive
system is generally reliable when operating in its normal environments. What is also
revealed is the unreliability of human cognitive system in artificial or extreme
circumstances. Many people think of the latter finding as something that could
deprive much of the explanatory value of evolutionary epistemology. Surely human
cognitive system is not infallible, but it is curious as to why this would reduce the
explanatory weight of any evolutionary approach to epistemology. Doesn’t the fact
that we are able to find out that we are prone to certain sorts of cognitive errors in
certain types of cognitive situations just demonstrate how reliable human cognitive
system could be when it is supplemented with scientific method? And isn’t it
reasonable to suppose that scientific method is in turn grounded in the general
reliability of human cognitive system? These are all questions that could be further
explored by evolutionary epistemology.
The Quinean and Popperian approaches to evolutionary epistemology find their
inspiration from Darwinism, through which the philosophical concerns about human
knowledge are able to reach out to a variety of well-developed traditional
evolutionary disciplines—e.g., anthropology, evolutionary biology, ethology, and
primatology, etc.—and a cluster of rapidly blooming new evolutionary studies—e.g.,
sociobiology, memetics, and evolutionary psychology, etc. These fields of
evolutionary paradigm have provided many invaluable insights on some of the most
perplexing philosophical questions—e.g., “How do we know?”, “Why should we be
moral?”, “What is our place in nature?”, “Who are we?”, and so forth. Philosophers
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could avail themselves a great deal by reflecting on the acute observations and
inventive hypotheses made by the scientists working in evolutionary tradition. In
return, scientists of relevant disciplines would also be grandly benefited by the keen
senses and critical skills of philosophers. A deeper understanding on the nature of
human knowledge could be expected to be arisen from such a collaborative endeavor
between philosophers and scientists.
18
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