The Competitiveness of Nations in a Global Knowledge-Based Economy
Thomas S. Kuhn
*The Road since Structure
Proceedings of the Biennial Meeting
of the
Philosophy of Science
Association,
Issue Volume Two: Symposia and Invited
Papers, 1990
* Massachusetts Institute of
Technology
On this occasion, and in this place, I feel that I
ought, and am probably expected, to look back at the things which have happened
to the philosophy of science since I first began to take an interest in it over
half a century ago. But I am both
too much an outsider and too much a protagonist to undertake that assignment.
Rather than attempt to situate the
present state of philosophy of science with respect to its past - a subject on
which I’ve little authority - I shall try to situate my present state in
philosophy of science with respect to its own past - a subject on which, however
imperfect, I’m probably the best authority there is.
As a number of you know, I’m at work on a book, and what
I mean to attempt here is an exceedingly brief and dogmatic sketch of its main
themes. I think of my project as a
return, now underway for a decade, to the philosophical problems left over from
the Structure of Scientific Revolutions. But it might better be described more
generally, as a study of the problems raised by the transition to what’s
sometimes called the historical and sometimes (at least by Clark Glymour,
speaking to me) just the “soft” philosophy of science. That’s a transition for which I get far
more credit, and also more blame, than I have coming to me. I was, if you will, present at the
creation, and it wasn’t very crowded. But others were present too: Paul
Feyerabend and Russ Hanson, in particular, as well as Mary Hesse, Michael
Polanyi, Stephen Toulmin, and a few more besides. Whatever a Zeitgeist is, we
provided a striking illustration of its role in intellectual
affairs.
Returning to my projected book, you will not be
surprised to hear that the main targets at which it aims are such issues as
rationality, relativism and, most particularly, realism and truth. But they’re not primarily what the book
is about, what occupies most space in it. That role is taken instead by
incommensurability. No other aspect
of Structure has concerned me so deeply in the thirty years since the
book was written, and I emerge from those years feeling more strongly than ever
that incommensurability has to be an essential component of any historical,
developmental, or evolutionary view of scientific knowledge. Properly understood - something I’ve by
no means always managed myself - incommensurability is far from being the threat
to rational evaluation of truth claims that it has frequently seemed. Rather, it’s what is needed, within a
developmental perspective, to restore some badly needed bite to the
whole
3
notion of cognitive evaluation. It is needed, that is, to defend notions
like truth and knowledge from, for example, the excesses of post-modernist
movements like the strong program. Clearly, I can’t hope to make all that
out here: it’s a project for a book. But I shall try, however sketchily, to
describe the main elements of the position the book develops. I begin by saying something about what I
now take incommensurability to be, and then attempt to sketch its relationship
to questions of relativism, truth, and realism. In the book, the issue of rationality
will figure, too, but there is no space here even to sketch its
role.
Incommensurability is a notion that for me emerged from
attempts to understand apparently nonsensical passages encountered in old
scientific texts. Ordinarily they
had been taken as evidence of the author’s confused or mistaken beliefs. My experiences led me to suggest,
instead, that those passages were being misread: the appearance of nonsense
could be removed by recovering older meanings for some of the terms involved,
meanings different from those subsequently current. During the years since, I’ve often spoken
metaphorically of the process by which later meanings had been produced from
earlier ones as a process of language change. And, more recently, I’ve spoken also of
the historian’s recovery of older meanings as a process of language learning
rather like that undergone by the fictional anthropologist whom Quine
misdescribes as a radical translator (Kuhn 1983a). The ability to learn a language does not,
I’ve emphasized, guarantee the ability to translate into or out of
it.
By now, however, the language metaphor seems to me far
too inclusive. To the extent that
I’m concerned with language and with meanings at all - an issue to which I’ll
shortly return - it is with the meanings of a restricted class of terms. Roughly speaking, they are taxonomic
terms or kind terms, a widespread category that includes natural kinds,
artifactual kinds, social kinds, and probably others. In English the class is coextensive, or
nearly so, with the terms that by themselves or within appropriate phrases can
take the indefinite article. These
are primarily the count nouns together with the mass nouns, words which combine
with count nouns in phrases that take the indefinite article. Some terms require still further tests
hinging, for example, on permissible suffixes.
Terms of this sort have two essential properties. First, as already indicated, they are
marked or labelled as kind terms by virtue of lexical characteristics like
taking the indefinite article. Being a kind term is thus part of what
the word means, part of what one must have in the head to use the word properly.
Second - a limitation I sometimes
refer to as the no-overlap principle - no two kind terms, no two terms with the
kind label, may overlap in their referents unless they are related as species to
genus. There are no dogs that are
also cats, no gold rings that are also silver rings, and so on: that’s what
makes dogs, cats, silver, and gold each a kind. Therefore, if the members of a language
community encounter a dog that’s also a cat (or, more realistically, a creature
like the duck-billed platypus), they cannot just enrich the set of category
terms but must instead redesign a part of the taxonomy. Pace, the causal theorists of reference,
‘water’ did not always refer to H20 (Kuhn 1987; 1990, pp.
309-14).
Notice now that a lexical taxonomy of some sort must be
in place before description of the world can begin. Shared taxonomic categories, at least in
an area under discussion, are prerequisite to unproblematic communication,
including the communication required for the evaluation of truth claims. If different speech communities have
taxonomies that differ in some local area, then members of one of them can (and
occasionally will) make statements that, though fully meaningful within that
speech community, cannot in principle be articulated by members of the other.
To bridge the gap between
communities would require adding to one lexicon a kind-term that
over-
4
laps, shares a referent, with one that is already in
place. It is that situation which
the no-overlap principle precludes.
Incommensurability thus becomes a sort of
untranslatability, localized to one or another area in which two lexical
taxonomies differ. The differences
which produce it are not any old differences, but ones that violate either the
no-overlap condition, the kind-label condition1 or else a restriction
on hierarchical relations that I cannot spell out here. Violations of those sorts do not bar
intercommunity understanding.
Members of one community can acquire the taxonomy employed by members of
an-other, as the historian does in learning to understand old texts. But the process which permits
understanding produces bilinguals, not translators, and bilingualism has a cost,
which will be particularly important to what follows. The bilingual must always remember within
which community discourse is occurring. The use of one taxonomy to make
statements to someone who uses the other places communication at
risk.
Let me formulate these points in one more way, and then
make a last remark about them. Given a lexical taxonomy, or what I’ll
mostly now call simply a lexicon, there are all sorts of different statements
that can be made, and all sorts of theories that can be developed. Standard techniques will lead to some of
these being accepted as true, others rejected as false. But there are also statements which could
be made, theories which could be developed, within some other taxonomy but which
cannot be made with this one and vice versa. The first volume of Lyons’ Semantics
(1977, pp. 237-8) contains a wonderfully simple example, which some of you
will know: the impossibility of translating the English statement, “the cat sat
on the mat”, into French, because of the incommensurability between the French
and English taxonomies for floor coverings. In each particular case for which the
English statement is true, one can find a co-referential French statement, some
using ‘tapis’, others ‘paillasson,’ still others ‘carpette,’ and so on. But there is no single French statement
which refers to all and only the situations in which the English statement is
true. In that sense, the English
statement cannot be made in French. In a similar vein, I’ve elsewhere pointed
out (Kuhn 1987, p. 8) that the content of the Copernican statement, “planets
travel around the sun”, cannot be expressed in a statement that invokes the
celestial taxonomy of the Ptolemaic statement, “planets travel around the
earth”. The difference between the
two statements is not simply one of fact. The term ‘planet’ appears as a kind term
in both, and the two kinds overlap in membership without either’s containing all
the celestial bodies contained in the other. All of which is to say that there are
episodes in scientific development which involve fundamental change in some
taxonomic categories and which therefore confront later observers with problems
like those the ethnologist encounters when trying to break into another
culture.
A final remark will close this sketch of my current
views on incommensurability. I have
described those views as concerned with words and with lexical taxonomy,
and I shall continue in that mode: the sorts of knowledge I deal with come in
explicit verbal or related symbolic forms. But it may clarify what I have in mind to
suggest that I might more appropriately speak of concepts than of words. What I have been calling a lexical
taxonomy might, that is, better be called a conceptual scheme, where the “very
notion” of a conceptual scheme is not that of a set of beliefs but of a
particular operating mode of a mental module prerequisite to having beliefs, a
mode that at once supplies and bounds the set of beliefs it is possible to
conceive. Some such taxonomic
module I take to be pre-linguistic and possessed by animals. Presumably it evolved originally for the
sensory, most obviously for the visual, system. In the book I shall give reasons for
supposing that it developed from a still more fundamental mechanism which
enables individual living organisms to reidentify other substances by tracing
their spatio-temporal trajectories.
5
I shall be coming back to incommensurability, but let me
for now set it aside in order to sketch the developmental framework within which
it functions. Since I must again
move quickly and often cryptically, I begin by anticipating the direction in
which I am headed. Basically, I
shall be trying to sketch the form which I think any viable evolutionary
epistemology has to take. I shall,
that is, be returning to the evolutionary analogy introduced in the very last
pages of the first edition of Structure, attempting both to clarify it
and to push it further. During the
thirty years since I first made that evolutionary move, theories of the
evolution both of species and of knowledge have, of course, been transformed in
ways I am only beginning to discover. I still have much to learn, but to date
the fit seems extremely good.
I start from points familiar to many of you. When I first got involved, a generation
ago, with the enterprise now often called historical philosophy of science, I
and most of my coworkers thought history functioned as a source of empirical
evidence. That evidence we found in
historical case studies, which forced us to pay close attention to science as it
really was. Now I think we
overemphasized the empirical aspect of our enterprise (an evolutionary
epistemology need not be a naturalized one). What has for me emerged as essential is
not so much the details of historical cases as the perspective or the ideology
that attention to historical cases brings with it. The historian, that is, always picks up a
process already underway, its beginnings lost in earlier time. Beliefs are already in place; they
provide the basis for the ongoing research whose results will in some cases
change them; research in their absence is unimaginable though there has
nevertheless been a long tradition of imagining it. For the historian, in short, no
Archimedean platform is available for the pursuit of science other than the
historically situated one already in place. If you approach science as an historian
must, little observation of its actual practice is required to reach conclusions
of this sort.
Such conclusions have by now been pretty generally
accepted: I scarcely know a foundationalist any more. But for me, this way of abandoning
foundationalism has a further consequence which, though widely discussed, is by
no means widely or fully accepted. The discussions I have in mind usually
proceed under the rubric of the rationality or relativity of truth claims, but
these labels misdirect attention. Though both rationality and relativism
are somehow implicated, what is fundamentally at stake is rather the
correspondence theory of truth, the notion that the goal, when evaluating
scientific laws or theories, is to determine whether or not they correspond to
an external, mind-independent world. It is that notion, whether in an absolute
or probabilistic form, that I’m persuaded must vanish together with
foundationalism. What replaces it
will still require a strong conception of truth, but not, except in the most
trivial sense, correspondence truth.
Let me at least suggest what the argument involves.
On the developmental view,
scientific knowledge claims are necessarily evaluated from a moving,
historically-situated, Archimedian platform. What requires evaluation cannot be an
individual proposition embodying a knowledge claim in isolation: embracing a new
knowledge claim typically requires adjustment of other beliefs as well. Nor is it the entire body of knowledge
claims that would result if that proposition were accepted. Rather, what’s to be evaluated is the
desirability of a particular change-of-belief, a change which would alter the
existing body of knowledge claims so as to incorporate, with minimum disruption,
the new claim as well. Judgements
of this sort are necessarily comparative: which of two bodies of knowledge - the
original or the proposed alternative - is better for doing whatever it is
that scientists do. And that is the
case whether what scientists do is solve puzzles (my view), improve empirical
adequacy (Bas van Frassen’s), or increase the dominance of the ruling elite (in
parody, the strong program’s). I
do, of course, have my own preference among these
alternatives,
6
and it makes a difference (Kuhn, 1983b). But no choice between them is relevant to
what’s presently at stake.
In comparative judgements of the kind just sketched,
shared beliefs are left in place: they serve as the given for purposes of the
current evaluation; they provide a replacement for the traditional Archimedean
platform. The fact that they may -
indeed probably will - later be at risk in some other evaluation is simply
irrelevant. Nothing about the
rationality of the outcome of the current evaluation depends upon their, in
fact, being true or false. They are
simply in place, part of the historical situation within which this evaluation
is made. But if the actual truth
value of the shared presumptions required for the evaluation is irrelevant, then
the question of the truth or falsity of the changes made or rejected on the
basis of that evaluation cannot arise either. A number of classic problems in
philosophy of science - most obviously Duhemian holism - turn out on this view
to be due not to the nature of scientific knowledge but to a misperception of
what justification of belief is all about. Justification does not aim at a goal
external to the historical situation but simply, in that situation, at improving
the tools available for the job at hand.
To this point I have been trying to firm-up and extend
the parallel between scientific and biological development suggested at the end
of the first edition of Structure: scientific development must be seen as
a process driven from behind, not pulled from ahead - as evolution from, rather
than evolution towards. In making
that suggestion, as elsewhere in the book, the parallel I had in mind was
diachronic, involving the relation between older and more recent scientific
beliefs about the same or overlapping ranges of natural phenomena. Now I want to suggest a second, less
widely perceived parallel between Darwinian evolution and the evolution of
knowledge, one that cuts a synchronic slice across the sciences rather than a
diachronic slice containing one of them. Though I have in the past occasionally
spoken of the incommensurability between the theories of contemporary scientific
specialties, I’ve only in the last few years begun to see its significance to
the parallels between biological evolution and scientific development. Those parallels have also been
persuasively emphasized recently in a splendid article by Mario Biagioli of UCLA
(1990). To both of us they seem
extremely important, though we emphasize them for somewhat different
reasons.
To indicate what is involved I must revert briefly to my
old distinction between normal and revolutionary development. In Structure it was the
distinction between those developments that simply add to knowledge, and those
which require giving up part of what’s been believed before. In the new book it will emerge as the
distinction between developments which do and developments which do not require
local taxonomic change. (The
alteration permits a significantly more nuanced description of what goes on
during revolutionary change than I’ve been able to provide before.) During this second sort of change,
something else occurs that in Structure got mentioned only in passing.
After a revolution there are
usually (perhaps always) more cognitive specialties or fields of knowledge than
there were before. Either a new
branch has split off from the parent trunk, as scientific specialties have
repeatedly split off in the past from philosophy and from medicine. Or else a new specialty has been born at
an area of apparent overlap between two preexisting specialties, as occurred,
for example, in the cases of physical chemistry and molecular biology. At the time of its occurrence this second
sort of split is often hailed as a reunification of the sciences, as was the
case in the episodes just mentioned. As time goes on, however, one notices
that the new shoot seldom or never gets assimilated to either of its parents.
Instead, it becomes one more
separate specialty, gradually acquiring its own new specialists’ journals, a new
professional society, and often also new university chairs, laboratories, and
even departments. Over time a
diagram of the evolution of scientific fields, specialties, and
sub-specialties
7
comes to look strikingly like a layman’s diagram for a
biological evolutionary tree. Each
of these fields has a distinct lexicon, though the differences are local,
occuring only here and there. There
is no lingua franca capable of expressing, in its entirety, the content
of them all or even of any pair.
With much reluctance I have increasingly come to feel
that this process of specialization, with its consequent limitation on
communication and community, is inescapable, a consequence of first principles.
Specialization and the narrowing of
the range of expertise now look to me like the necessary price of increasingly
powerful cognitive tools. What’s
involved is the same sort of development of special tools for special functions
that’s apparent also in technological practice. And, if that is the case, then a couple
of additional parallels between biological evolution and the evolution of
knowledge come to seem especially consequential. First, revolutions, which produce new
divisions between fields in scientific development, are much like episodes of
speciation in biological evolution. The biological parallel to revolutionary
change is not mutation, as I thought for many years, but speciation. And the problems presented by speciation
(e.g., the difficulty in identifying an episode of speciation until some time
after it has occurred, and the impossibility, even then, of dating the time of
its occurrence) are very similar to those presented by revolutionary change and
by the emergence and individuation of new scientific
specialties.
The second parallel between biological and scientific
development, to which I return again in the concluding section, concerns the
unit which undergoes speciation (not to be confused with a unit of selection).
In the biological case, it is a
reproductively isolated population, a unit whose members collectively embody the
gene pool which ensures both the population’s self-perpetuation and its
continuing isolation. In the
scientific case, the unit is a community of intercommunicating specialists, a
unit whose members share a lexicon that provides the basis for both the conduct
and the evaluation of their research and which simultaneously, by barring full
communication with those outside the group, maintains their isolation from
practitioners of other specialties.
To anyone who values the unity of knowledge, this aspect
of specialization - lexical or taxonomic divergence, with consequent limitations
on communication - is a condition to be deplored. But such unity may be in principle an
unattainable goal, and its energetic pursuit might well place the growth of
knowledge at risk. Lexical
diversity and the principled limit it imposes on communication may be the
isolating mechanism required for the development of knowledge. Very likely it is the specialization
consequent on lexical diversity that permits the sciences, viewed collectively,
to solve the puzzles posed by a wider range of natural phenomena than a
lexically-homogenous science could achieve.
Though I greet the thought with mixed feelings, I am
increasingly persuaded that the limited range of possible partners for fruitful
intercourse is the essential precondition for what is known as progress in both
biological development and the development of knowledge. When I suggested earlier that
incommensurability, properly understood, could reveal the source of the
cognitive bite and authority of the sciences, its role as an isolating mechanism
was prerequisite to the topic I had principally in mind, the one to which I now
turn.
This reference to ‘intercourse’, for which I shall
henceforth substitute the term ‘discourse’, bring me back to problems concerning
truth, and thus to the locus of the newly restored bite. I said earlier that we must learn to get
along without anything at all like a correspondence theory of truth. But something like a redundancy theory of
truth is badly needed to replace it, something that will introduce minimal laws
of
8
logic (in particular, the law of non-contradiction) and
make adhering to them a precondition for the rationality of evaluations (Horwich
1990). On this view, as I wish to
employ it, the essential function of the concept of truth is to require choice
between acceptance and rejection of a statement or a theory in the face of
evidence shared by all. Let me try
briefly to sketch what I have in mind.
Ian Hacking, in an attempt (1982) to denature the
apparent relativism associated with incommensurability, spoke of the way in
which new “styles” introduce into science new candidates for true/false. Since that time, I’ve been gradually
realizing (the reformulation is still in process) that some of my own central
points are far better made without speaking of statements as themselves being
true or as being false. Instead,
the evaluation of a putatively scientific statement should be conceived as
comprising two seldom-separated parts. First, determine the status of the
statement: is it a candidate for true/false? To that question, as you’ll shortly see,
the answer is lexicon-dependent. And second, supposing a positive answer
to the first, is the statement rationally assertable? To that question, given a lexicon, the
answer is properly found by something like the normal rules of
evidence.
In this reformulation, to declare a statement a
candidate for true/false is to accept it as a counter in a language game whose
rules forbid asserting both a statement and its contrary. A person who breaks that rule declares
him or herself outside the game. If
one nevertheless tries to continue play, then discourse breaks down; the
integrity of the language community is threatened. Similar, though more problematic, rules
apply, not simply to contrary statements, but more generally to logically
incompatible ones. There are, of
course, language games without the rule of non-contradiction and its relatives:
poetry and mystical discourse, for example. And there are also, even within the
declarative-statement game, recognized ways of bracketing the rule, permitting
and even exploiting the use of contradiction. Metaphor and other tropes are the most
obvious examples; more central for present purposes are the historian’s
restatements of past beliefs. (Though the originals were candidates for
true/false, the historian’s later restatements - made by a bilingual speaking
the language of one culture to the members of another -are not.) But in the sciences and in many more
ordinary community activities, such bracketing devices are parasitic on normal
discourse. And these activities -
the ones that presuppose normal adherence to the rules of the true/false game -
are an essential ingredient of the glue that binds communities together. In one form or another, the rules of the
true/false game are thus universals for all human communities. But the result of applying those rules
varies from one speech community to the next. In discussion between members of
communities with differently structured lexicons, assertability and evidence
play the same role for both only in areas (there are always a great many) where
the two lexicons are congruent.
Where the lexicons of the parties to discourse differ, a
given string of words will sometimes make different statements for each. A statement may be a candidate for
truth/falsity with one lexicon without having that status in the others. And even when it does, the two statements
will not be the same: though identically phrased, strong evidence for one need
not be evidence for the other. Communication breakdowns are then
inevitable, and it is to avoid them that the bilingual is forced to remember at
all times which lexicon is in play, which community the discourse is occurring
within.
These breakdowns in communication do, of course, occur:
they’re a significant characteristic of the episodes Structure referred
to as ‘crises’. I take them to be
the crucial symptoms of the speciation-like process through which new
disciplines emerge, each with it own lexicon, and each with its own area of
knowledge. It is by these
divisions, I’ve been suggesting, that knowledge grows. And it’s the need
to
9
maintain discourse, to keep the game of declarative
statements going, that forces these divisions and the fragmentation of knowledge
that results.
I close with some brief and tentative remarks about what
emerges from this position as the relationship between the lexicon - the shared
taxonomy of a speech community - and the world the members of that community
jointly inhabit. Clearly it cannot
be the one Putnam (1977, pp. 123-38) has called metaphysical realism. Insofar as the structure of the world can
be experienced and the experience communicated, it is constrained by the
structure of the lexicon of the community which inhabits it. Doubtless some aspects of that lexical
structure are biologically determined, the products of a shared phylogeny. But, at least among advanced creatures
(and not just those linguistically endowed), significant aspects are determined
also by education, by the process of socialization, that is, which initiates
neophytes into the community of their parents and peers. Creatures with the same biological
endowment may experience the world through lexicons that are here and there very
differently structured, and in those areas they will be unable to communicate
all of their experiences across the lexical divide. Though individuals may belong to several
interrelated communities (thus, be multilinguals), they experience aspects of
the world differently as they move from one to the next.
Remarks like these suggest that the world is somehow
mind-dependent, perhaps an invention or construction of the creatures which
inhabit it, and in recent years such suggestions have been widely pursued. But the metaphors of invention,
construction, and mind-dependence are in two respects grossly misleading. First, the world is not invented or
constructed. The creatures to whom
this responsibility is imputed, in fact, find the world already in place, its
rudiments at their birth and its increasingly full actuality during their
educational socialization, a socialization in which examples of the way the
world is play an essential part. That world, furthermore, has been
experientially given, in part to the new inhabitants directly, and in part
indirectly, by inheritance, embodying the experience of their forebears. As such, it is entirely solid: not in the
least respectful of an observer’s wishes and desires; quite capable of providing
decisive evidence against invented hypotheses which fail to match its behavior.
Creatures born into it must take it
as they find it. They can, of
course, interact with it, altering both it and themselves in the process, and
the populated world thus altered is the one that will be found in place by the
generation which follows. The point
closely parallels the one made earlier about the nature of evaluation seen from
a developmental perspective: there, what required evaluation was not belief but
change in some aspects of belief, the rest held fixed in the process; here, what
people can effect or invent is not the world but changes in some aspects of it,
the balance remaining as before. In
both cases, too, the changes that can be made are not introduced at will. Most proposal for change are rejected on
the evidence; the nature of those that remain can rarely be foreseen; and the
consequences of accepting one or another of them often prove to be
undesired.
Can a world that alters with time and from one community
to the next correspond to what is generally referred to as “the real world”?
I do not see how its right to that
title can be denied. It provides
the environment, the stage, for all individual and social life. On such life it places rigid constraints;
continued existence depends on adaptation to them; and in the modern world
scientific activity has become a primary tool for adaptation. What more can reasonably be asked of a
real world?
In the penultimate sentence, above, the word
‘adaptation’ is clearly problematic. Can the members of a group properly be
said to adapt to an environment which they are constantly adjusting to fit their
needs? Is it the creatures who
adapt to the world or
10
does the world adapt to the creatures? Doesn’t this whole way of talking imply a
mutual plasticity incompatible with the rigidity of the constraints that make
the world real and that made it appropriate to describe the creatures as adapted
to it? These difficulties are
genuine, but they necessarily inhere in any and all descriptions of undirected
evolutionary processes. The
identical problem is, for example, currently the subject of much discussion in
evolutionary biology. On the one
hand the evolutionary process gives rise to creatures more and more closely
adapted to a narrower and narrower biological niche. On the other, the niche to which they are
adapted is recognizable only in retrospect, with its population in place: it has
no existence independent of the community which is adapted to it. (Lewontin
1978.) What actually evolves,
therefore, is creatures and niches together: what creates the tensions inherent
in talk of adaptation is the need, if discussion and analysis are to be
possible, to draw a line between the creatures within the niche, on the one
hand, and their “external” environment, on the other.
Niches may not seem to be worlds, but the difference is
one of viewpoint. Niches are where
other creatures live. We see
them from outside and thus in physical interaction with their inhabitants. But the inhabitants of a niche see it
from inside and their interactions with it are, to them, intentionally mediated
through something like a mental representation. Biologically, that is, a niche is the
world of the group which inhabits it, thus constituting it a niche. Conceptually, the world is our
representation of our niche, the residence of the particular human
community with whose members we are currently interacting.
The world-constitutive role assigned here to
intentionality and mental representations recurs to a theme characteristic of my
viewpoint throughout its long development: compare my earlier recourse to
gestalt switches, seeing as understanding, and so on. This is the aspect of my work that, more
than any other, has suggested that I took the world to be mind-dependent. But the metaphor of a mind-dependent
world - like its cousin, the constructed or invented world - proves to be deeply
misleading. It is groups and
group-practices that constitute worlds (and are constituted by them). And the practice-in-the-world of some of
those groups is science. The
primary unit through which the sciences develop is thus, as previously stressed,
the group, and groups do not have minds. Under the unfortunate title, “Are species
individuals?”, contemporary biological theory offers a significant parallel
(Hull, 1976, provides an especially useful introduction to the literature).
In one sense the procreating
organisms which perpetuate a species are the units whose practice permits
evolution to occur. But to
understand the outcome of that process one must see the evolutionary unit (not
to be confused with a unit of selection) as the gene pool shared by those
organisms, the organisms which carry the gene pool serving only as the parts
which, through bi-sexual reproduction, exchange genes within the population.
Cognitive evolution depends,
similarly, upon the exchange, through discourse, of statements within a
community. Though the units which
exchange those statements are individual scientists, understanding the advance
of knowledge, the outcome of their practice, depends upon seeing them as atoms
constitutive of a larger whole, the community of practitioners of some
scientific specialty.
The primacy of the community over its members is
reflected also in the theory of the lexicon, the unit which embodies the shared
conceptual or taxonomic structure that holds the community together and
simultaneously isolates it from other groups. Conceive the lexicon as a module within
the head of an individual group member. It can then be shown (though not here)
that what characterizes members of the group is possession not of identical
lexicons, but of mutually congruent ones, of lexicons with the same structure.
The lexical structure which
characterizes a group is more abstract
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than, different in kind from, the individual lexicons or
mental modules which embody it. And
it is only that structure, not its various individual embodiments, that members
of the community must share. The
mechanics of taxonomizing are in this respect like its function: neither can be
fully understood except as grounded within the community it
serves.
By now it may be clear that the position I’m developing
is a sort of post-Darwinian Kantianism. Like the Kantian categories, the lexicon
supplies preconditions of possible experience. But lexical categories, unlike their
Kantian forebears, can and do change, both with time and with the passage from
one community to another. None of
those changes, of course, is ever vast. Whether the communities in question are
displaced in time or in conceptual space, their lexical structures must overlap
in major ways or there could be no bridgeheads permitting a member of one to
acquire the lexicon of the other. Nor, in the absence of major overlap,
would it be possible for the members of a single community to evaluate proposed
new theories when their acceptance required lexical change. Small changes, however, can have
large-scale effects. The Copernican
Revolution provides especially well-known illustrations.
Underlying all these processes of differentiation and
change, there must, of course, be something permanent, fixed, and stable. But, like Kant’s Ding an sich, it
is ineffable, undescribable, undiscussible. Located outside of space and time, this
Kantian source of stability is the whole from which have been fabricated both
creatures and their niches, both the “internal” and the “external” worlds. Experience and description are possible
only with the described and describer separated, and the lexical structure which
marks that separation can do so in different ways, each resulting in a
different, though never wholly different, form of life. Some ways are better suited to some
purposes, some to others. But none
is to be accepted as true or rejected as false; none gives privileged access to
a real, as against an invented, world. The ways of being-in-the-world which a
lexicon provides are not candidates for true/false.
References
Biagioli, M. (1990), “The Anthropology of
Incommensurability,” Studies in History and Philosophy of Science 21:
183-209.
Hacking,
Horwich, P. (1990), Truth.
Kuhn, T.S. (1983a), “Commensurability, Comparability, Communicability,” PSA 1982, Volume Two.
(1987), “What are Scientific Revolutions?” in The Probabilistic Revolution, Volume 1: Ideas in History, L. Kruger, U. Daston, and M. Heidelberger (eds.).
12
(1990), “Dubbing and Redubbing: the Vulnerabiltity of Rigid Designation,” in Scientific Theories,
Lyons, J. (1977), Semantics,
Lewontin, R.C. (1978), “Adaptation,” Scientific
American 239: 212-30.
Putnam, H. (1978), Meaning and the Moral Sciences.
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