«J.D. Trout Philosophy Department and the Parmly Hearing Institute Loyola University of Chicago Introduction In the grand tradition, philosophical ...»
Ontological Progress in Science
Richard M. Burian
Center for the Study of Science in Society and Department of Philosophy
Virginia Polytechnic Institute and State University
Philosophy Department and the Parmly Hearing Institute
Loyola University of Chicago
In the grand tradition, philosophical ontology was considered logically and
epistemologically prior to scientific ontology. Like many contemporary philosophers of science,
we consider this a mistake. There is a two-way traffic between philosophical and scientific ontologies; the more we learn about what there actually is, the more we learn about what can be and what must be, and vice versa. But that is not the present topic; here we focus on the ontology or ontologies of science, not traditional philosophical ontologies or the traffic between scientific and philosophical ontologies.
As will soon be obvious, the problem of ontological progress in science, thus restricted, still offers plenty to hold us. We will address the following four theses, which we will support
with some fragmentary arguments:
1. The ontology of science is intensely compositional and hierarchical.
2. Although much of science is reductionistic, the reductionism in question is generally not eliminative.
3. Current philosophers' treatments of the ontology (or ontologies) of science are far too intimately tied to the latest or the `best' theory. Finally,
4. A central form of ontological progress in science—we believe the central form— consists in obtaining significant contact with, and accurate characterizations of, entities, processes, properties, events, and states (henceforth, simply 'entities'), further and further removed from those that are perceptually available to us.
We shall utilize this framework of theses to suggest some preliminary responses to the sceptical arguments of such philosophers as Larry Laudan and Bas van Fraassen against the idea that there is ontological progress in science. There is not space on this occasion to attempt a proper rebuttal of the arguments they employ to undercut scientific realism, but the general line that we would pursue in constructing such rebuttals will become clear in the course of this paper.
Burian and Trout Ontological Progress in Science We have been greatly influenced by many recent writings attacking and defending scientific realism1 and by discussions with many friends concerning this topic.2 However, in order to carry out the constructive program of the paper we shall make but scant reference to the recent literature or the views of others. On occasion we will indicate certain of the differences between the position here espoused and those put forward by some of the leading authorities who have published on this topic.
Scientific Ontologies A plausible defense of scientific realism will be philosophically complex. Ultimately, the best evidence for scientific realism depends on the results of some collection of secure, welldeveloped theories. At the same time, scientific realism ought not be tied too tightly to particular scientific theories, especially speculative ones at the pioneering frontiers of research. One reason for this is that scientific realism, at least as we conceive it, is less closely allied to familiar styles of philosophical or "formal" ontology than is usually recognized. Most scientists' answers to questions like "What kinds of things have been discovered by your science?" or "What sorts of entities are required by the best theories in your field?" do not have the sort of (intended) ultimacy that characterizes the answers to questions in formal ontology.
A scientist often answers to such questions by speaking of some sorts of entities—e.g., of quarks, of electrons and protons, of different isotopes of the same chemical element, of DNA and RNA molecules, of membrane bound and soluble proteins, of the Golgi apparatus and ribosomes, of tectonic plates, of dynamic equilibria, or of spiral galaxies, black holes, and quasars. Such answers usually are not (and certainly need not be) so closely tied to a particular account or theory of the structure or the workings of the entities in question as to rule out alternative theories of the same entities. Indeed, answers of this sort can be put forward without any commitment to what philosophers would consider an account of the `ultimate ontological status' of the entities in question. (We mean to include here such matters as whether the entities are
1. A representative sample of the literature may be found in the following books: Nancy Cartwright, How the Laws of Physics Lie, (Oxford and New York: Oxford University Press, 1983); Paul Churchland and Clifford Hooker (eds.), Images of Science (Chicago: The University of Chicago Press, 1985); Arthur Fine, The Shaky Game (Chicago: The University of Chicago Press, 1986); Bas van Fraassen, The Scientific Image (Oxford: Oxford University Press, 1980), and Laws and Symmetry (Oxford: Oxford University Press, 1989); Ronald Giere, Explaining Science (Chicago: The University of Chicago Press, 1988); Ian Hacking, Representing and Intervening (Cambridge: Cambridge University Press, 1983); Larry Laudan, Progress and its Problems (Berkeley: University of California Press, 1977);
Jarrett Leplin (ed.), Scientific Realism (Berkeley: University of California Press, 1984); Joseph Margolis, Pragmatism Without Foundations (Oxford: Basil Blackwell, 1986); and W. H. Newton-Smith, The Rationality of Science (London: Routledge and Kegan Paul, 1981).
2. We include particularly Richard Boyd, Michael Krausz, Larry Laudan, Jarrett Leplin, Joe Margolis, Deborah Mayo, Alan Musgrave, Joe Pitt, Bob Richardson, and Nils Roll-Hansen as well as various members of the Piedmont Philosophy of Science Discussion Group. We are also grateful to discussants at seminars in the Departments of Philosophy of Virginia Polytechnic Institute and State University, the University of California, Davis, the University of Hawaii at Manoa, The Ohio State University, and the Universities of Tromso, Trondheim, and Oslo, and to many others for constructive suggestions.
Burian and Trout Ontological Progress in Science simple or complex, if complex whether they are `mere aggregates' or essentially structured, how they fit into the relevant system of categories, and so on.) It follows almost immediately that the ontological status of scientific entities cannot simply be read off a theory that countenances and describes them, not even when it is the latest and best such theory. For what the scientist is committed to (rightly or wrongly) is the existence and causal importance of entities that might well come to be located or individuated in ways not yet available. It might well turn out that the entities in question are seriously misdescribed by all currently available theories, e.g., that they belong to different formal ontological categories than current theories suggest.3 To the extent that this is correct, we should be mistrustful of philosophical attempts to analyze the ontological commitments of a scientific discipline (or of, say, the atomic theory of matter, the gene theory of heredity, or quantum electrodynamics) by means of an analysis of the (supposedly) best theories on the forefront of the relevant discipline.
In fact, there are at least three distinct reasons for distrusting analysis of the latest and best theories of science as the central tool by means of which to tease out its ontological commitments. The first is that theories themselves are embedded in a larger context. Evaluation of the claims implicit in theories often requires considerable knowledge of that context. Many theories, after all, are "models," "working theories," or "idealizations," not meant to be definitive. Often theories incorporate, in one way or another, idealizations and approximations that limit their application within narrow limits. For example, the treatment of a gas as a cloud of molecules is sometimes meant to serve as a useful model, as a means of making predictions or constructing tests of a theory, rather than as a literal description. In such cases serious mistakes often follow from reading ontological significance into an analysis of the theory in question, especially since (as the next two points make clear) contextual knowledge often contains independent information bearing on the evaluation of the ontological status of the entities in question. There may, for example, be experimental or observational means of securing reference or obtaining access to the entities or interactions of concern independent of that particular theory.
The second reason for caution is that the theory as a unit of analysis is (at least usually) too small. By this we mean not only that theories typically constitute attempts to explain or understand a domain of phenomena that is at least in part independently characterized and identified, but also that the very same science contains (or can properly come to contain) alternative theories that attempt significantly different accounts of the same phenomena or entities, perhaps even linking different subsets of the entities to different domains. To the extent that this is correct, the science has (evolving) ontological commitments not fully or decisively reflected in whichever `best' theory one examines.
3. Thus for more than a decade, W. Bateson and T. H. Morgan differed about the ultimate structure of genes. Bateson thought that they were some sort of stable resonances that could not be located on chromosomes while Morgan thought them to be material particles with chromosomal locations. In disagreements of this character there is no way to be certain which party, if either, will prove to be right, though (of course) both cannot be. Nonetheless, the fundamental disagreements between these two theorists did not prevent them from securing thorough, experimentally anchored agreement about the referent of such terms as `the gene for dwarfing in peas'. Such agreement could discriminate between distinct genes with similar or identical effects. For a few more details and some references, cf. Richard Burian, "On Conceptual Change in Biology: The Case of the Gene," in D. Depew and B. Weber (eds.), Evolution at a Crossroads (Cambridge, Ma.: MIT Press, 1985), pp. 21-42, esp. pp.
Burian and Trout Ontological Progress in Science Finally, we often have access to the phenomena of a domain with which a theory is concerned that is (at least in good part) independent of that theory or of the differences between it and various alternative theories. At points where theoretical domains make contact, different theories may refer to the same entities—as when ions referred to in chemistry are also referred to in membrane biology, for example, to describe the process of ion transfer across cell membranes.
It is for this reason that multiple independent confirmation and theoretical integration are such potent sources of evidence for scientific realism about entities. In such cases, the process of developing and testing alternative theories to explain the phenomena of the domain can sometimes take advantage of the avenues of independent access to resolve experimentally the disagreements that arise, including disagreements over the correct ontology and perhaps the very integrity of the domain in question. But this means that our analyses must cope with ontological disagreement within a science or between sciences and must account for our occasional ability to resolve such disagreements by use of experiments. We are sometimes in a position to resolve such questions as whether electrons "really" can be spatio-temporally localized within an arbitrary tolerance. If we peg the ontology of a science to its latest best theory, we cannot properly parse the issues in cases of this sort, nor will our conceptual apparatus allow us to perform a satisfactory analysis of the procedures that achieve resolution of such disputes.
It follows that the relationship between our theories and our assessments of the ontological status of the theoretical entities they purport to designate is far more complex than has been acknowledged in traditional versions of scientific realism, tied as they are to the analysis of well formulated versions of particular theories. In particular, the formal characterization of the relevant theoretical entities within a theory is not (and ought not be) the sole means of identifying, localizing, or characterizing the entities in question; otherwise it would be impossible to construct tests of claims about the principal features alleged by the theory to characterize those entities. The fact that successful tests of such claims are not just possible but actual, indicates that scientific realism about entities depends at least in some measure on our knowledge of true, non-accidental generalizations—in short, knowledge of laws—concerning those entities.4 Against Eliminative Reduction Beyond the excessive theory-centrism of some versions of scientific realism, the current literature on this topic is flawed by the implicit commitment of many realist authors to some form of eliminative (micro)reductionism. At stake is the notion that the ontologically important entities discovered by science are physically smaller constituents of familiar or larger-scale objects and events. Whatever the importance for formal ontology of a successful mereological analysis of an entity or class of entities (i.e., an exhaustive analysis of those entities into a set or structure of "lower level" parts), a scientific analysis of an entity into its constituent parts does not and should not by itself count as the reduction of the "higher level" entity to those constituents.5
4. We mean 'law' in no stronger or more committed sense than that used here.