The Competitiveness of Nations in a Global Knowledge-Based Economy
Hans-Jorg Rheinberger * **
Experimental Complexity in Biology:
Some Epistemological and Historical Remarks
Philosophy of Science
Vol.
64, Supplement
Dec. 1997, S245-S254.
|
Content
3. The Gene as a
Fluctuating Object of Molecular Biology
4. Conjunctures, Hybrids,
Bifurcations, Experimental Cultures |
My paper draws on examples from
molecular biology, the details of which I have developed elsewhere (Rheinberger 1992, 1993, 1995, 1997). Here, I can give only a brief outline of my
argument. Reduction of complexity is a
prerequisite for experimental research. To
make sense of the universe of living beings, the modern biologist is bound to
divide his world into fragments in which parameters can be defined, quantities
measured, qualities identified. Such is
the nature of any “experimental system.” Ontic
complexity has to be reduced in order to make experimental research
possible. The complexity of the research
object, however, is epistemically retained
in the rich context of an experimental landscape, where the eruption of
“volcanic systems” can change the scenery dramatically as the result of
particular, unprecedented findings.
1.
Epistemology. The following
remarks are not aimed at a philosophy of biological complexity. Rather, the intent of my deliberations is epistemological.
Epistemology is concerned with the
spatial and temporal structure, the noumenal modus vivendi, and the material character of the activities involved
in engendering scientific objects. It
does not pretend to describe or to explain the properties of these objects
themselves. Epistemology deals with the
properties of scientific practice, the practice of biology in the event.
My claim is this: having a close look at what life scientists do when
they occupy themselves with the objects of their experimental procedures may
lead to a better understanding of scientific practice in gen-
* Max Planck
Institute for the History of Science, Wilhelmstr.
44, D-10117 Berlin, Germany.
** Richard Burian and Lindley Darden are acknowledged for their patience, help, and criticism.
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eral. Above all, it seems to me, this concerns the
role and the status of sharply bounded concepts as well as the predictive force
of explicitly formulated theories.
In closely following the historical path of biological
practices, we may arrive at a view of how the sciences operate that is quite
different from views that have taken classical physics as their point of
departure. With this statement, I do not
intend a counter-colonial conquista, nor do I wish to
revive the age-old and weary debate traditionally labeled a critique of
“reductionism,” and I offer no holistic remedies. Much has been said about constitutive,
explanatory, and theoretical reduction in recent years (see Sarkar
1991 for a succinct summary). I do not
want to add to this philosophical debate. Let me adopt, instead, a different point of
view, less theory-inclined and more practice-centered, of the sciences as an
irreducibly multilayered ensemble of epistemic practices.
2. Experimental Systems. The basic concept I envisage
as a point of orientation in the hypercomplex network
of the modern empirical sciences, and of the life sciences in particular, is
that of the “experimental system.” The
notion is firmly entrenched in the everyday practice and vernacular of
twentieth-century life scientists, especially of biochemists and molecular
biologists. Scientists use the term to
characterize the scope, as well as the limits and the constraints, of their
research activities. Ask a laboratory
scientist what he is doing, and he will speak to you about his “system.” Experimental systems constitute integral, locally
manageable, functional units of scientific research. It is through them that particular scientific
objects - epistemic things in my terminology - gain prominence in a wider field
of epistemic cultures and practices. These
practices include instruments and inscription devices as well as model
organisms to which biological research objects are inextricably tied. Theorems become attached to and detached from
them in a rather contingent manner. As
William Bechtel and Robert Richardson (1993) demonstrated in Discovering
Complexity, strategies of “decomposition” and of “localization” are crucial
to the analysis of such systems.
Consequently, on an epistemological level we need, to
quote Gaston Bachelard, a “philosophy of
epistemological detail,” the counterpart to what he calls the “integral philosophy
of the philosophers” (Bachelard 1966, 12, 14). Many philosophers have seen in this situation
a deplorable and detrimental, yet intrinsic limitation to empirical knowledge. I argue that this is a mistake. We should recognize that, properly analyzed,
the details and particulars of practice, far from imposing limits on our
knowledge, are prerequisites for, and provide the very means of, achieving
scientific knowledge. In particular, it
is in the fabric
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of properly “tuned” experimental systems that
scientific events materialize. It is in
the nature of an event that it cannot be anticipated. Novelties are always the result of
spatiotemporal singularities. Experimental
systems are precisely the arrangements that allow scientists to create
epistemic spatiotemporal singularities. They
allow researchers to arrive at unprecedented, surprising results. In this sense, such systems are “more real,”
if you will, than ordinary reality. The
reality of epistemic things is their resistance, their resilience, their
capacity, as “jokers” of practice, to force us to abandon preconceptions and
anticipations. To cite Michael Polanyi: “This capacity of a thing to reveal itself in
unexpected ways in the future, I attribute to the fact that the thing observed
is an aspect of reality, possessing a significance that is not exhausted by our
conception of any single aspect of it. To
trust that a thing we know is real is, in this sense, to feel that it has the
independence and power for manifesting itself in yet unthought
of ways in the future” (quoted in Grene 1984, 219). From the perspective of scientific research,
this is the best definition of “reality” I have encountered so far.
I have shown elsewhere that productive experimental
systems are located at the cutting edge of the decompostition
and localization procedure just mentioned (Rheinberger
1992, 1997). They operate most
prolifically at the fuzzy boundary between the trivial and the complex. Experimental systems are machines for reducing
complexity, but to escape triviality, they must remain connected to the
complexity of an “epistemic horizon.” It
is the network of surrounding experimental systems that makes each of its
elements take on its epistemic value. If
ontic complexity has to be reduced in order to make
experimental research possible, this very complexity is epistemically
retained in the rich context of an experimental landscape, in which new
connections and disconnections can happen at any time, and where the boundaries
of a scientific object continually fluctuate.
3. The Gene as a Fluctuating Object
of Molecular Biology. In this section, I very briefly touch on the changing
epistemic and experimental fate of the “gene” as one of the prime epistemic
objects of molecular biology. The few
remarks that follow are not meant as a systematic assessment of the intricate
pathways through which molecular biology has appropriated this object. Nor can I retrace the meandering history of
the gene as an object of experimentation in molecular biology. My concern is simply to point out, in a rather
loose and associative fashion, some questions that I think will have to be
addressed if we wish to understand experimental complexity. We will see that instead of solving the riddle
of the gene and rescuing it forever from the deep unknown, molecular biology
has managed to redefine its boundaries repeatedly.
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Today, biologists continue to reshape this strange epistemic object and
to alter it almost beyond recognition.
Molecular biology is a hybrid science combining
physics, chemistry, genetics, and the search for biological function at the
molecular level. Not surprisingly, it
presents itself as conceptually hybrid as well, which is not to say that it has
no consistency. The discourse of
molecular biology pervades contemporary biology as a whole. I would like to learn more about such hybrid
consistencies: how they come about, how they work, and how they evolve.
Let me give a few examples of perspectives on genes
both enabled and constrained by experimental systems on these different levels.
For a biophysicist working with a
crystalline DNA fiber, a gene might be sufficiently characterized by a particular
conformation of a DNA double helix. If
asked, he or she might define a gene in terms of the atomic coordinates of a
nucleic acid. For a biochemist working
with isolated DNA in the test tube, genes might be sufficiently defined as
stretches of nucleic acids exhibiting certain stereochemical
features and sequence recognition patterns. The biochemist can reasonably try to give a
macromolecular, DNA-based definition of the gene. For a molecular geneticist, genes might be
defined as instructive elements of chromosomes that eventually give rise to
defined functional or structural products: transfer RNAs,
ribosomal RNAs, enzymes, and proteins serving other
purposes. Molecular geneticists
certainly will insist on considering issues in terms of replication,
transcription, and translation and will require examination of the products of
hereditary units when speaking of genes. For evolutionary molecular biologists, genes
might be the products of mutating, reshuffling, duplicating, transposing, and
rear-ranging bits of DNA within a complex chromosomal environment that has
evolved through differential reproduction and selection. Therefore, they will rely on concepts such as
transmission, lineage, and history. For
developmental biologists, genes might be sufficiently described, on the one
hand, as hierarchically ordered switches that, when turned on or off, induce
differentiation, and on the other hand, as patches of instructions that are
realized in synchrony through the action of these switches. Thus, developmental biologists are likely to
refer to the regulatory aspect of genetic circuitry when defining a gene or a
larger transcriptional unit such as an operon. We could go on and add more items to the list.
We can ask whether it is necessary or even desirable
to have a unified concept of the gene in order to hold all these disciplinary
specializations together and to develop them in a coordinated fashion. Obviously, this has not been needed in the
half century since molecular biology came into existence. I do not think that it would have helped the
development
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of the field in appreciable ways; further, I
contend that an attempt to do so today would produce nothing more than an
exercise in rhetoric. The coherence of
molecular biology - which does not exclude Kuhnian incommensurabilities - is not tied into an axiomatic
structure or an algorithm; it is embedded in a complex set of experimental
systems, each with its genuine epistemic practices, that have evolved over time
and that have constrained earlier interpretations as well as allowed new
ambiguities to arise. Genes as we now
know them are boundary objects par excellence that are crafted, more than by
any theory, by the practices and instruments that helped to create the new
biology.
4. Conjunctures, Hybrids,
Bifurcations, Experimental Cultures. Let me come back to the concerns of
epistemology and sort out, if only in preliminary fashion, a few features of
such webs of epistemic activities. If
experimentation has “a life of its own” with respect to theories (Hacking 1983,
150), experimental
systems, as we have glimpsed through the short discussion of the molecular
“gene” above, do not live alone for that reason. The number of such systems is enormous, and
variation among them is a prerequisite for experimental complexity to come into
play. With Peter Coveney
and Roger Highfield (1995, 7), we can state that
complexity like this rests on “macroscopic collections of such units that are
endowed with the potential to evolve in time,” whose “interactions lead to
coherent collective phenomena.”
Such interactions can be specified. The collective action of experimental systems
may lead to “conjunctures,” meaning the emergence of an extraordinary
constellation. The notion should not be
confounded with that of an “anomaly” or with that of a “paradigm shift” in the
sense of Thomas Kuhn (1962). It designates
neither an irritating irregularity within an established and accepted conceptual
framework nor the replacement of an encompassing theory by a new one; rather,
it points to unforeseen directions opened up within the experimental process. Conjunctures derive from unprecedented events
and may lead to major rearrangements and recombinations
of given representational spaces in an experimental system. Unprecedented events are about things not
sought after - they come as a surprise, but nevertheless do not just happen. They are made to happen through the inner
workings of the experimental machinery “for making the future” (Jacob 1988, 9),
and yet, they may lead experimenters to completely change the direction of
their research activities. Conjunctures
can take different forms, and it remains for historical case studies to
elaborate these forms in depth.
To illustrate this point, let me give a brief example
whose details can be found elsewhere (Rheinberger
1997). In 1953, a first test tube system
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of protein synthesis was established. Its dependence on ATP as a supply of
biochemical energy led, in 1954, to the characterization of a novel epistemic
entity: activated amino acids consisting of a combination of an amino acid, the
building block of proteins, and a molecule of ATP lacking two of its
phosphates. With that, protein synthesis
became detached from the earlier context of oncology and inserted into general
biochemistry. Two years later, in pursuit
of this biochemical perspective, yet another molecule emerged as an additional
intermediate of the protein synthesis reaction chain. It was a small ribonucleic acid to which the
activated amino acids became attached before condensing to protein molecules. Today, this new epistemic entity is known as transfer
RNA. A major conjuncture followed from
this finding. First identified as an
intermediate in a biochemical reaction chain, transfer RNA was soon to become
an intermediary in genetic information transfer. It bridged the gap between the genes as carriers
of genetic specificity, and between the proteins as carriers of biological
specificity in terms of cellular function. As a result, the experimental system of in
vitro protein synthesis became part of molecular biology.
There is another kind of event deriving from the fuzzy
contours of experimental systems: events that produce linkages between independent
systems, thus leading to hybrid formations. Interfaces can be created between two or more
experimental arrangements. Such coincidences
connect particular experimental systems to integrated setups. From a hybridization of different, originally
unconnected experimental systems, research arrangements with totally unexpected
qualities can result. Things thus are
brought together whose articulation, amalgamation, or even blending was not
assumed to lie in the “nature” of these things. The history of molecular biology is replete
with hybridization events. The fusion,
e.g., of Francois Jacob’s bacterial conjugation and phage replication system
with Jacques Monod’s system of induced enzyme
synthesis led to the emergence of another novel RNA entity, messenger RNA, and
to a pathbreaking model of genetic regulation.
A third type of event is complementary to
hybridization. It can result in the
bifurcation of a particular experimental system and thus lead to offspring
systems. Such offspring arrangements
tend to form ensembles, or clusters, that yield an experimental space for
enlarged scientific communities. Generally speaking, bifurcations of an
experimental system occur when it has reached a level of complexity that allows
researchers to pursue slightly divergent, but sufficiently different epistemic
tracks to enable them to arrive at significantly different results. Typically, clusters of such bifurcated systems
remain linked for a while by sharing one or more of their material constituents
and so may take advantage of each other’s achievements or of each other’s
services. But this must not nec-
S250
essarily remain so. They can become completely disconnected from
the maternal system, or integrated into other ensembles.
To provide an example, let us return to transfer RNA. With this molecule, the point was reached
where in vitro systems of protein synthesis began to proliferate and to develop
in diverging directions. Different
research agendas arose. Characterizing
the nucleotide sequence of transfer RNA promised insights into the secrets of
the genetic code. Probing the
interaction of transfer RNA with ribosomes attracted
many research groups interested in the molecular mechanism of decoding. And the replacement of rat liver in vitro
systems with systems based on E. coli extracts opened the possibility to
link the genetics of this organism with detailed studies of its physiology.
Concepts such as conjuncture, hybridization, and
bifurcation permit us to envisage ensembles of experimental systems and to
articulate their intricate interactions. They permit us to conceive of a structured experimental
network of objects and practices that, just as in the case of individual
experimental systems, is tinkered and pulled together from different elements. The cohesion of such a reticulum of
experimental practices and systems is not conceptual in the first place. It is due to, and reaches exactly as far as,
the circulation and the exchange of epistemic entities, model compounds,
technical subroutines, and tacit skills throughout the network. Conjunctures, hybridizations, and bifurcations
basically describe types of shifts, linkages, and descents through which the
dynamics of reorientation, fusion, and proliferation of particular experimental
systems is made possible. The
consideration of these processes permits us to extend the epistemic analysis
from the microdynamics of localized and situated
experimental settings to the larger dynamics of cultures of experimentation.
Epistemic things (such as the gene and transfer RNA), experimental systems, ensembles of such systems, and experimental cultures are the conceptual elements with which I try to prepare the ground for a history and epistemology of experimentation that dissolves the traditional distinction between context of justification and context of discovery. Such an epistemology of scientific practice frees the experiment from its subsidiary role in rationalistic accounts of theory development and theory change. My framework, however, does not focus on the social history of scientific institutions and disciplines. It is an attempt to understand the epistemic dynamics of the empirical sciences in terms of the structure of the practices from which these sciences spring and in which they dwell. Experimental cultures are as “patchwork” as the experimental systems they are composed of. But they are held together by a specific kind of glue: material, not only formal, interaction; and practice-centered, not merely theoretical, compatibility.
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5.
The Patchwork View of Research.
With this, we come very near to one of the ideas - and remain very far from others - that Stuart Kauffman develops in his recent book (1995), and which he calls the “patch procedure”:
The basic idea of the patch procedure is
simple: take a hard, conflict-laden task in which many parts interact, and
divide it into a quilt of nonoverlapping patches. Try to optimize within each patch. As this occurs, the couplings between parts in
two patches across patch boundaries will mean that finding a “good” solution in
one patch will change the problem to be solved by the part in the adjacent
patches. Since changes in each patch
will alter the problems confronted by the neighboring patches, and the adaptive
moves by those patches in turn will alter the problem faced by yet other
patches, the system is just like our model coevolving ecosystems... We are about to see that if the entire
conflict-laden task is broken into the properly chosen patches, the coevolving
system lies at a phase transition between order and chaos and rapidly finds
very good solutions. Patches, in short,
may be a fundamental process we have evolved in our social systems, and perhaps
elsewhere, to solve very hard problems. (Kauffman 1995, 252-253)
In its application to science, let me call this the
“patchwork view of research.” To
understand its workings, we have to look for a transition zone that lies
somewhere between the rationality of individual actors and the constraints of
disciplinary communities. The patches,
i.e., the experimental systems, are the subcritical
elements of a network that, as a whole, takes on the features of a supracritical process we call science in the making. For the time being, of course, this does not
amount to much more than a seductive metaphor. The few remarks I have presented in the
central section of my paper on the gene as a boundary object in molecular
biology are scarcely more than shreds that may hint at the direction to be
taken. We have only started to look at
the non-Cartesian, emergent properties of the inextricable web of epistemic
practices that unfolds in utterly unforeseeable ways but nevertheless shows a
pattern.
How shall we describe this endeavor? There are resources. In his Inaugural Address to the College de
France in 1970, Michel Foucault traced a series of notions that will prove
helpful for assessing the historical dynamics of scientific practice: “The
fundamental notions now imposed upon us are no longer those of consciousness
and continuity (with their correlative problems of liberty and causality), nor
are they those of sign and structure. They are notions, rather, of events and of
series, with the group of notions linked to these [including regularity,
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the aleatoric, discontinuity, dependence, and
transformation] it is around such an ensemble that this analysis of discourse I
am thinking of is articulated, certainly not upon those traditional themes
which the philosophers of the past took for ‘living history’” (Foucault 1972b,
230). [1] Foucault
(1972a, esp. Part 4) has characterized his version of such an endeavor as
“archeology” and, with respect to the history of science, has spoken of an
“archeology of knowledge.” The
archeologist digs out the material sediments, the dispositions and depositions
in which all theoretical knowledge is embodied and embedded.
6. Conclusion. At the end of his
previously-mentioned book, Kauffman ponders: “I wonder if we really understand
very much of what we are creating”; and he continues: “All we can do is be
locally wise, even though our own best efforts will ultimately create the
conditions that lead to our transformations to utterly unforeseeable ways of
being” (Kauffman 1995, 298, 303). Local
wisdom, at best, is what characterizes the practice of an endeavor that has
never ceased to depict itself as an allegedly global undertaking: Science. Instead of searching for universal theories,
the order of the day for epistemology is to learn to understand how local
wisdoms, entrenched in research “attractors” such as experimental systems,
become connected to knowledge patch-works. Fragmentation, far from being deleterious, appears
as one of the basic conditions of unprecedented development. Fragmentation, aiming at simplicity, finally
creates complexity. The research object
called the “gene” is a good historical example for this process. The many dimensions it has acquired in the
course of the last century are not the result of alternative, organismic or holistic approaches called up to counteract reductionistic genetics and molecular biology. On the contrary, local experimental
sophistication has exploded a coarse and simplistic gene concept from within. Currently, we are witnessing a similar
scenario on the level of what, we used to call
biological “disciplines”: the boosting of developmental biology through
molecular genetics. Understanding the
dynamics of these interactions and transformations is what a “philosophy of the
epistemological detail” will have to address.
“There is an incompatibility between precision and
complexity. As the complexity of a
system increases, our ability to make precise and yet non-trivial assertions
about its behavior diminishes” (Zadeh 1987, 23). Exploring this epistemological principle of
uncertainty in an effort to manage experimental complexity requires less
striving at a “Theory
1. The insertion has been omitted from the English
translation.
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of Everything” (Pickering 1995) than looking for
patterns of “moderate compressibility” (Coveney and Highfield 1995, 39).
Bachelard, G. (1966), La Philosophie
du Non, 4th ed. Paris: Presses Universitaires de France.
Bechtel, W. and R. C.
Richardson (1993), Discovering Complexity: Decomposition and Localization as
Strategies in Scientific Research. Princeton: Princeton University Press.
Coveney, P. and R. Highfield (1995),
Frontiers of Complexity: The Search for Order in a Chaotic World. London:
Faber and Faber.
Foucault, M. (1972a), The Archaeology of Knowledge. Translated by A. M. Sheridan Smith. New York: Pantheon
Books.
(1972b), The
Discourse on Language.Translated
by Rupert Swyer. Published as an
appendix to The Archaeology of Knowledge. New York: Pantheon
Books.
Grene, M. (1984), The
Knower and the Known. Washington, DC: Center for Advanced Research in
Phenomenology & University Press of America.
Hacking, I. (1983), Representing
and Intervening: Introductory Topics in the Philosophy of Natural Science. Cambridge:
Cambridge University Press.
Jacob, F. (1988), The Statue Within. New York: Basic Books.
Kauffman, 5. (1995), At Home in the Universe. Oxford:
Oxford University Press.
Kuhn, T. 5. (1962), The Structure of Scientific Revolutions. Chicago:
The University of Chicago Press.
Pickering, A. (1995), The Mangle of Practice. Chicago: The
University of Chicago Press.
Rheinberger, H.-J.
(1992), “Experiment, Difference, and Writing. I. Tracing
Protein Synthesis,” and “II. The Laboratory Production of transfer RNA”,
Studies in History and Philosophy of Science 23: 305-331, 389-422.
(1993),
“Experiment and Orientation. Early Systems of in Vitro Protein Synthesis,” Journal of the
History of Biology 26: 443-471.
(1995), “From Microsomes to Ribosomes:
“Strategies’ of ‘Representation”, Journal of the History of Biology 28:
49-89.
(1997), Towards History of Epistemic
Things: Synthesizing Proteins in the Test Tube. Stanford: Stanford University
Press.
Sarkar, 5.
(1991),
“Reductionism and Functional Explanation in Molecular Biology”, Uroboros 1: 67-94.
Zadeh, L. (1987), “Coping with the Imprecision of the Real
World”, in R. R. Yager, S. Ovchinnikov,
R. M. Tong, and H. T. Nguyen (eds.), Fuzzy Sets and Applications: Selected
Papers by Lofti A. Zadeh. New
York: John Wiley, pp. 9-28.
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