Who is a scientific realist

Editorial team. Add an entry to this list:. Ladymanin ja Rossin verifikaatioperiaate ei kuitenkaan Induction in General Philosophy of Science.

Modality in Metaphysics. Naturalism in Metaphilosophy. Scientific Realism in General Philosophy of Science. Remove from this list Direct download Translate. In their recent article, Graber and Golemon argue that any attempted evolutionary debunking of naturalism faces a dilemma. First, in order to be evolutionarily plausible, the skeptical implications must not be too broad.

Second, in order to constitute a genuine challenge to scientific realism, the skeptical implications must not be too narrow. Graber and Golemon further develop an evolutionary debunking argument that avoids both horns of this dilemma. The ultimate result will be both a better understanding of the desiderata and the argumentative contours of a successful evolutionary debunking argument.

Evolutionary Biology in Philosophy of Biology. Philosophy of Religion. Remove from this list Direct download 2 more Translate. Chemistry in Natural Sciences. Emergence in Metaphysics. Ontology in Metaphysics. Realism in Chemistry in Philosophy of Physical Science. Structure in Chemistry in Philosophy of Physical Science. Peut-on pratiquer la sociologie comme on pratique les sciences naturelles? Experimentation in Science in General Philosophy of Science.

Philosophy of Sociology in Philosophy of Social Science. Rationality in Epistemology. Scientific Method in General Philosophy of Science. Scientific Models in General Philosophy of Science. According to scientific realists, the predictive success of mature theories provides a strong epistemic basis for thinking that such theories are approximately true. However, we know that many theories once regarded as well-confirmed and predictively successful were eventually replaced with successor theories, and some claim this undermines the epistemic confidence we should have in the approximate truth of current science.

Selective scientific realists in turn argue that if one can show that the predictive success of some rejected theory T is Showing that the predictive success of a failed theory is the result of theoretical features later rejected provides a counterexample to SSR.

Conversely, SSR is supported if its explanation of the predictive success of failed theories--namely, that the factors which lead to predictive success in the failed theory survive in the successor theory--is able to handle a wide array of historical cases.

Most contemporary proponents of scientific realism advocate some form of selective realism. One of the most prominent variants is the working posits view, which claims that the essential propositions of a successful theory are those that are involved in the actual derivations of predictions.

In this paper, I offer a systematic examination of this view, surveying no fewer than six competing interpretations of it. I argue, however, that none is satisfactory. A general reason to reject the working posits view is Remove from this list Direct download 2 more.

A more circumspect reading of the former is proffered that discloses where the so far not fully appreciated, real challenges lie for realism about gravitational energy. Their arguments are critically examined. Special attention is devoted to the But the concern is unfounded: the qualifications are all independently motivated, and indeed necessary given the philosophical complexity.

Qualifications are to be welcomed here; often the truth is far from Remove from this list Direct download 5 more. In this sense, for Smith, These themes are illustrated primarily through his writings on the history of astronomy.

History of Physics in Philosophy of Physical Science. Philosophy of Social Science. Empiricism, Misc in Metaphilosophy. Pierre Duhem in 19th Century Philosophy. Remove from this list Direct download. Decades of debate about scientific realism notwithstanding, we find ourselves bemused by what different philosophers appear to think it is, exactly. Does it require any sort of belief in relation to scientific theories and, if so, what sort?

Is it rather typified by a certain understanding of the rationality of such beliefs? In the following dialogue we explore these questions in hopes of clarifying some convictions about what scientific realism is, and what it could or should be.

En route, we Freedom and Liberty in Social and Political Philosophy. Remove from this list Direct download 4 more. Explanatory elucidation occurs when a theory has one or more of its assumptions explained by another independently successful theory.

Because explanatory elucidation springs from independently supported theories, it improves the credibility of the assumptions it casts light on, hence its relevance for realists.

But cases can be pointed to where explanatory elucidation has badly failed to identify truthful components. One way to address this challenge is by trying to find additional epistemic support for seemingly meritorious theory-parts. Resource in this regard, I suggest, include some specific lines of probing that regularly turn up against theories in mature scientific disciplines.

Together with explanatory elucidation, those lines single out, in diachronic fashion, theory components worthy of realist commitment, or so I argue. This article explores and attempts to resolve some issues that arise when at stake is the need to harmonize philosophical hermeneutics with a kind of realist philosophy of science.

The author takes issue with established position in the realism-antirealism controversy. Interventionism is criticized for a residual Cartesian dualism. Cognitive relativism is debated by developing a concept of situated transcendence in the constitution of objects of inquiry. Non-behaviorist arguments against scheme-content dualism are advanced that appeal to context- sensitive theory of meaning.

Social constructivism is rejected for the hypostatization of epistemic positions. The article suggests a model of the constitution of meaning. It undertakes an attempt at demonstrating how the integration of this model in a hermeneutic philosophy of science leads to realism without epistemological representationalism, foundationalism, and cognitive essentialism. The article is oriented toward a new dialogue between hermeneutic phenomenology and a holistic epistemology. If it is problematic, this is arguably a concern primarily for certain forms of antirealism, which adopt an epistemically positive attitude only with respect to the observable.

It is not ultimately a concern for scientific realism, which does not discriminate epistemically between observables and unobservables per se. Before considering the nuances of what scientific realism entails, it is useful to distinguish between two different kinds of definition in this context.

Most commonly, the position is described in terms of the epistemic achievements constituted by scientific theories and models—this qualification will be taken as given henceforth. On this approach, scientific realism is a position concerning the actual epistemic status of theories or some components thereof , and this is described in a number of ways.

For example, most people define scientific realism in terms of the truth or approximate truth of scientific theories or certain aspects of theories. Some define it in terms of the successful reference of theoretical terms to things in the world, both observable and unobservable. Others define scientific realism not in terms of truth or reference, but in terms of belief in the ontology of scientific theories.

What all of these approaches have in common is a commitment to the idea that our best theories have a certain epistemic status: they yield knowledge of aspects of the world, including unobservable aspects.

For definitions along these lines, see Smart ; Boyd ; Devitt ; Kukla ; Niiniluoto ; Psillos ; and Chakravartty a. Another way to think about scientific realism is in terms of the epistemic aims of scientific inquiry van Fraassen 8; Lyons That is, some think of the position in terms of what science aims to do: the scientific realist holds that science aims to produce true descriptions of things in the world or approximately true descriptions, or ones whose central terms successfully refer, and so on.

There is a weak implication here to the effect that if science aims at truth, and scientific practice is at all successful, the characterization of scientific realism in terms of aim may then entail some form of characterization in terms of achievement. But this is not a strict implication, since defining scientific realism in terms of aiming at truth does not, strictly speaking, suggest anything about the success of scientific practice in this regard.

For this reason, some take the aspirational characterization of scientific realism to be too weak Kitcher ; Devitt n. Most scientific realists commit to something more in terms of achievement, and this is assumed in what follows. The description of scientific realism as a positive epistemic attitude toward theories, including parts putatively concerning the unobservable, is a kind of shorthand for more precise commitments Kukla ch.

Traditionally, realism more generally is associated with any position that endorses belief in the reality of something. But what, more precisely, is that?

In order to be clear about what realism in the context of the sciences amounts to, and to differentiate it from some important antirealist alternatives, it is useful to understand it in terms of three dimensions: a metaphysical or ontological dimension; a semantic dimension; and an epistemological dimension. Metaphysically, realism is committed to the mind-independent existence of the world investigated by the sciences. This idea is best clarified in contrast with positions that deny it. This sort of idealism, however, though historically important, is rarely encountered in contemporary philosophy of science.

More common rejections of mind-independence stem from neo-Kantian views of the nature of scientific knowledge, which deny that the world of our experience is mind-independent, even if in some cases these positions accept that the world in itself does not depend on the existence of minds.

It is important to note in this connection that human convention in scientific taxonomy is compatible with mind-independence. Semantically, realism is committed to a literal interpretation of scientific claims about the world. Traditionally, instrumentalism holds that claims about unobservable things have no literal meaning at all though the term is often used more liberally in connection with some antirealist positions today.

Some antirealists contend that claims involving unobservables should not be interpreted literally, but as elliptical for corresponding claims about observables. These positions are described in more detail in section 4.

Epistemologically, realism is committed to the idea that theoretical claims interpreted literally as describing a mind-independent reality constitute knowledge of the world. This contrasts with skeptical positions which, even if they grant the metaphysical and semantic dimensions of realism, doubt that scientific investigation is epistemologically powerful enough to yield such knowledge, or, as in the case of some antirealist positions, insist that it is only powerful enough to yield knowledge regarding observables.

The epistemological dimension of realism, though shared by realists generally, is sometimes described more specifically in contrary ways.

For example, while many realists subscribe to the truth or approximate truth of theories understood in terms of some version of the correspondence theory of truth as suggested by Fine a and contested by Ellis , some prefer a truthmaker account Asay or a deflationary account of truth Giere 82; Devitt ; Leeds Amidst these differences, however, a general recipe for realism is widely shared: our best scientific theories give true or approximately true descriptions of observable and unobservable aspects of a mind-independent world.

The general recipe for realism just described is accurate so far as it goes, but still falls short of the degree of precision offered by most realists. The motivation for these qualifications is perhaps clear. If one is to defend a positive epistemic attitude regarding scientific theories, it is presumably sensible to do so not merely in connection with any theory especially when one considers that, over the long history of the sciences up to the present, some theories were not or are not especially successful , but rather with respect to theories or aspects of theories, as we will see momentarily that would appear, prima facie , to merit such a defense, viz.

The challenge of making these qualifications more precise, however, is significant, and has generated much discussion. Consider first the issue of how best to identify those theories that realists should be realists about. A general disclaimer is in order here: realists are generally fallibilists, holding that realism is appropriate in connection with our best theories even though they likely cannot be proven with absolute certainty; some of our best theories could conceivably turn out to be significantly mistaken, but realists maintain that, granting this possibility, there are grounds for realism nonetheless.

These grounds are bolstered by restricting the domain of theories suitable for realist commitment to those that are sufficiently mature and non- ad hoc Worrall —; Psillos — On these construals, however, both the notion of maturity and the notion of being non- ad hoc are admittedly vague.

One strategy for adding precision here is to attribute these qualities to theories that make successful, novel predictions. Alai Talk of approximate truth is often invoked in this context and has produced a significant amount of often highly technical work, conceptualizing the approximation of truth as something that can be quantified, such that judgments of relative approximate truth of one proposition or theory in comparison to another can be formalized and given precise definitions.

This work provides one possible means by which to consider the convergentist claim that theories can be viewed as increasingly approximately true over time, and this possibility is further considered in section 3.

A final and especially important qualification to the general recipe for realism described above comes in the form of a number of variations. These species of generic realism can be viewed as falling into three families or camps: explanationist realism; entity realism; and structural realism.

There is a shared principle of speciation here, in that all three approaches are attempts to identify more specifically the component parts of scientific theories that are most worthy of epistemic commitment.

Explanationism recommends realist commitment with respect to those parts of our best theories—regarding unobservable entities, laws, etc. Entity realism is the view that under conditions in which one can demonstrate impressive causal knowledge of a putative unobservable entity, such as knowledge that facilitates the manipulation of the entity and its use so as to intervene in other phenomena, one has good reason for realism regarding it.

Structural realism is the view that one should be a realist, not in connection with descriptions of the natures of things like unobservable entities found in our best theories, but rather with respect to their structure. All three of these positions adopt a strategy of selectivity, and this and the positions themselves are considered further in section 2.

Arguably, the fact that realists have endeavored to qualify their view and propose variations of it, as described above, suggests a collective moral: though some especially earlier discussions of realism give the impression that it is an attitude pertaining to science across the board, this is likely too coarse a way to understand the position.

Adopting a realist attitude toward the content of scientific theories does not entail that one believes all such content, but rather that one believes those aspects, including unobservable aspects, regarding which one takes such belief to be warranted, thus indicating a realism about those things more specifically.

The argument begins with the widely accepted premise that our best theories are extraordinarily successful: they facilitate empirical predictions, retrodictions, and explanations of the subject matters of scientific investigation, often marked by astounding accuracy and intricate causal manipulations of the relevant phenomena.

What explains this success? One explanation, favored by realists, is that our best theories are true or approximately true, or correctly describe a mind-independent world of entities, laws, etc. Indeed, if these theories were far from the truth, so the argument goes, the fact that they are so successful would be miraculous. And given the choice between a straightforward explanation of success and a miraculous explanation, clearly one should prefer the non-miraculous explanation, viz.

For elaborations of the miracle argument, see J. Brown ; Boyd ; Lipton ; Psillos ch. Though intuitively powerful, the miracle argument is contestable in a number of ways. One skeptical response is to question the very need for an explanation of the success of science in the first place. For example, van Fraassen 40; see also Wray , suggests that successful theories are analogous to well-adapted organisms—since only successful theories organisms survive, it is hardly surprising that our theories are successful, and therefore, there is no demand here for an explanation of success.

It is not entirely clear, however, whether the evolutionary analogy is sufficient to dissolve the intuition behind the miracle argument. One might wonder, for instance, why a particular theory is successful as opposed to why theories in general are successful , and the explanation sought may turn on specific features of the theory itself, including its descriptions of unobservables. Whether such explanations need be true, though, is a matter of debate.

While most theories of explanation require that the explanans be true, pragmatic theories of explanation do not van Fraassen ch. More generally, any epistemology of science that does not accept one or more of the three dimensions of realism—commitment to a mind-independent world, literal semantics, and epistemic access to unobservables—will thereby present a putative reason for resisting the miracle argument.

These positions are considered in section 4. Some authors contend that the miracle argument is, in fact, an instance of fallacious reasoning called the base rate fallacy Howson ch.

Consider the following illustration. If one tests positive, what are the chances that one has the disease? The lower the incidence of the disease at large, the lower the probability that a positive result signals the presence of the disease. By analogy, using the success of a scientific theory as an indicator of its approximate truth assuming a low rate of false positives—cases in which theories far from the truth are nonetheless successful is arguably, likewise, an instance of the base rate fallacy.

The success of a theory does not by itself suggest that it is likely approximately true, and since there is no independent way of knowing the base rate of approximately true theories, the chances of it being approximately true cannot be assessed.

Worrall unpublished, Other Internet Resources maintains that these contentions are ineffective against the miracle argument because they crucially depend on a misleading formalization of it in terms of probabilities cf. Menke ; for a criticism of the miracle argument based on a different probabilistic framing in terms of likelihoods, see Sober — If an unobservable entity is putatively capable of being detected by means of a scientific instrument or experiment, this may well form the basis of a defeasible argument for realism concerning it.

If, however, that same entity is putatively capable of being detected by not just one, but rather two or more different means of detection—forms of detection that are distinct with respect to the apparatuses they employ and the causal mechanisms and processes they are described as exploiting in the course of detection—this may serve as the basis of a significantly enhanced argument for realism cf.

Eronen Hacking ; see also Hacking — gives the example of dense bodies in red blood platelets that can be detected using different forms of microscopy. Different techniques of detection, such as those employed in light microscopy and transmission electron microscopy, make use of very different sorts of physical processes, and these operations are described theoretically in terms of correspondingly different causal mechanisms.

For similar examples, see Salmon — and Franklin —, — The argument from corroboration thus runs as follows. The fact that one and the same thing is apparently revealed by distinct modes of detection suggests that it would be an extraordinary coincidence if the supposed target of these revelations did not, in fact, exist.

The greater the extent to which detections can be corroborated by different means, the stronger the argument for realism regarding their putative target. The argument here can be viewed as resting on an intuition similar to that underlying the miracle argument: realism based on apparent detection may be only so compelling, but if different, theoretically independent means of detection produce the same result, suggesting the existence of one and the same unobservable, then realism provides a good explanation of the consilient evidence, in contrast with the arguably miraculous state of affairs in which theoretically independent techniques produce the same result in the absence of a shared target.

The idea that techniques of putative detection are often constructed or calibrated precisely with the intention of reproducing the outputs of others, however, may stand against the argument from corroboration.

Additionally, van Fraassen — argues that scientific explanations of evidential consilience may be accepted without the explanations themselves being understood as true, which once again raises questions about the nature of scientific explanation.

In section 1. This strategy is adopted in part to square realism with the widely accepted view that most if not all of even our best theories are false, strictly speaking. The most important variants of realism to implement this strategy are explanationism, entity realism, and structural realism. For related work pertaining to the notion of selectivity more generally, see R. Miller chs. Explanationists hold that a realist attitude can be justified in connection with unobservables described by our best theories precisely when appealing to those unobservables is indispensable or otherwise important to explaining why these theories are successful.

For example, if one takes successful novel prediction to be a hallmark of theories worthy of realist commitment generally, then explanationism suggests that, more specifically, those aspects of the theory that are essential to the derivation of such novel predictions are the parts of the theory most worthy of realist commitment.

Psillos chs. The immediate challenge to explanationism is to furnish a method with which to identify precisely those aspects of theories that are required for their success, in a way that is objective or principled enough to withstand the charge that realists are merely rationalizing post hoc , identifying the explanatorily crucial parts of past theories with aspects that have been retained in our current best theories.

Another version of realism that adopts the strategy of selectivity is entity realism. On this view, realist commitment is based on a putative ability to causally manipulate unobservable entities like electrons or gene sequences to a high degree—for example, to such a degree that one is able to intervene in other phenomena so as to bring about certain effects.

Miller ; Cartwright ch. Belief in scientific unobservables thus described is here partnered with a degree of skepticism about scientific theories more generally, and this raises questions about whether believing in entities while withholding belief with respect to the theories that describe them is a coherent or practicable combination Morrison ; Elsamahi ; Resnik ; Chakravartty ; Clarke ; Massimi Entity realism is especially compatible with and nicely facilitated by the causal theory of reference associated with Kripke and Putnam [b] ch.

Structural realism is another view promoting selectivity, but in this case it is the natures of unobservable entities that are viewed skeptically, with realism reserved for the structure of the unobservable realm, as represented by certain relations described by our best theories.

For ordinary scientific theories this is wrong. Scientists routinely supplement theories with well established auxiliary hypotheses in order to obtain observational predictions from them. So, it is probably best to think of the underdetermination argument as applying, not to "small" theories, but to "total sciences," large-scale conceptions of the world that might represent the total scientific conception of the world at a time.

Such a conception would already contain all of the auxiliary hypotheses which were legitimate by its lights, so the problem just mentioned does not arise. In this revised form the underdetermination argument says that--whatever our best scientific conception of the world may be at any given time--we will ever have any evidence that it embodies knowledge of unobservables.

It rests on a particular interpretation of an extremely plausible doctrine about factual knowledge. Traditional empiricism attributed to experience or sensation two different roles: experience was the source of all of our ideas--of the raw material for thinking--and experience was the only basis we have for justifying beliefs abut matters of fact. The first of these doctrines of empiricism has fallen on hard times, but the second doctrine called knowledge empiricism by Bennett enjoys widespread support.

In particular, it is an epistemological doctrine to which almost all scientific realists subscribe. The logical empiricist challenge to scientific realism arises from a quite plausible interpretation of knowledge empiricism according to which what it says is that there can be no evidence which rationally distinguishes between two empirically equivalent total sciences call this doctrine the evidential indistinguishability thesis , or the EIT.

It is part of a selectively skeptical program of anti-metaphysical "rational reconstruction. The result was supposed to be that scientific claims are meaningful and knowable early on, logical empiricists identified these two properties whereas "metaphysical" claims, because they are about unobservables, are at least unknowable and according to early versions of logical empiricism meaningless.

Now almost all actual science is conducted largely in a vocabulary consisting mainly of "theoretical terms": terms apparently referring to unobservables. It was definitely not the logical empiricists' project to reject such science. They intended to be selectively skeptical: to be skeptics about "metaphysics" but not about science. So, they embarked on a project of providing "rational reconstructions" of actual scientific theories and methods which were designed to eliminate any apparent commitments to knowledge of unobservables while still portraying actual scientific practices as sources of knowledge see, e.

In the case of scientific theories, the basic logical empiricist approaches were variations on the idea of instrumentalism , the view that scientific theories were predictive instruments and that the knowledge they represent is limited to what they predict about the observable properties of observables.

In the case of scientific methods, strategies for rational reconstruction have not been so easy to formulate. Here's the problem. Almost all of the methods scientists actually use in conducting experimental or observational studies are theory dependent : they depend for their justification on knowledge reflected in previously established theories.

Kuhn's discussion of "normal science" makes this point especially clearly, but all of the logical empiricists were acutely aware of it. Moreover, in sciences like physics, chemistry, molecular biology and astronomy, almost all of those methods seem prima facie to rest on knowledge of unobservable phenomena just think about the presuppositions of the design of any experiment in chemistry. What the project of rational reconstruction must show is that almost all of these methods can be reconstructed in such a way that their application, as guides to the identification of empirically adequate theories, does not require positing knowledge of unobservables.

The task of rationally reconstructing actual scientific methods has been the most significant challenge facing logical empiricism and related anti-realist approaches.

Instrumentalism and its variants provide a simple reconstruction of the content of scientific theories that pretty exactly fits the requirements of the project of rational reconstruction.

The depth of the theory dependence of scientific methods, and the extent to which they seem to depend on knowledge of unobservables, has posed a deeper challenge for logical empiricists and their allies. The fate of operationalism illustrates this challenge. Operationalism was a proposal for rationally reconstructing the use of "theoretical terms" terms that apparently refer to unobservables in science by treating those terms as being completely defined in terms of particular operational procedures, thereby eliminating the apparent references to unobservables.

Here's what operationalism says. For any theoretical term say, for example, "electron density" we can "rationally reconstruct" the use of that term by treating it as having an analytic operational definition in terms of laboratory procedures and instrumentation. So, for example, the operational definition of "electron density" might be given by a sentence of the form. Operationalism is not , for example, the idea that electron density is defined as whatever magnitude instruments of sort E reliably measure.

There is supposed to be no such thing as discovering, about E, , that some other instrument provides a more accurate value for electron density, or provides values for electron density under conditions where E doesn't function. Here again, thinking that there could be an improvement on E with respect to electron density requires thinking of electron density as a real feature of the world which E perhaps only approximately measures.

But, that's the realist conception which operationalism is designed to rationally reconstruct away. In actual, and apparently reliable, scientific practice, changes in the instrumentation associated with theoretical terms is utterly routine, and apparently crucial to the progress of science. Scientists routinely replace one instrument with another in order to achieve as they would say more accurate measurements of some unobservable magnitude -- often in the light of new theoretical developments -- or to permit measurement of it under conditions for which previous instrumentation was inadequate.

According to an operationalist conception, these sorts of modifications would not be methodologically acceptable. Most logical empiricists were not willing to accept this conclusion. After all, they intended to rationally reconstruct the best of actual scientific practice.

So most logical empiricists felt compelled to reject operationalism. Examples such as these made it clear that -- in apparently reliable scientific practice -- scientists behave as though 1 they obtain knowledge of unobservable as well as observable phenomena by deploying instruments which perhaps indirectly detect them, and 2 their theory dependent methodology in these and other matters is informed by knowledge of unobservables as well as of observables.

In particular, they appear to improve, or extend the range of, procedures for measuring or detecting unobservable phenomena in the light of theoretical knowledge of those phenomena. These features of scientific practice stimulated the articulation largely by philosophers in the empiricist tradition of two different but related arguments for scientific realism, to which we now turn our attention.

The fact that scientists, apparently justifiably, treat certain instruments and procedures as ways of detecting and measuring unobservable as well as observable phenomena led several philosophers see especially Feigl , Maxwell to adopt what amounts to a non-empiricist or, perhaps, more flexibly empiricist understanding of knowledge empiricism according to which 1 the special epistemic role of the senses derives from the fact that they are the only detectors we have built in to our bodies, but 2 the range of phenomena we can detect and measure can be broadened by extending the range of our senses through the use of instruments and procedures whose justification is theory dependent.

Thus knowledge of phenomena "unobservable" by traditional empiricists standards is possible. This sort of focus on laboratory detection and manipulation in defense of realism finds perhaps its most energetic expression in the writings of Hacking see, for example, Hacking The conception that instruments, designed with the help of theoretical understanding, can extend the range of the senses so as to provide information about unobservable phenomena surely has to be a component of any even remotely plausible defense of scientific realism.

Still, by itself the idea that instruments can extend the senses is inadequate as a rebuttal to the basic underdetermination argument. Here's why. The basic idea behind the extending-the-senses approach to defending scientific realism is that -- as scientists' knowledge of unobservable phenomena improves and as instrumental design becomes more sophisticated -- measurement and detection would become possible for phenomena hitherto beyond the reach of reliable detection and measurement; think of going from light microscopes, to electron microscopes, to x-ray crystallography devices which can produce images of atomic structures within crystals.

That has to be the realist's conception, but consider the effect of underdetermination arguments. Suppose that, at some stage in the process of the improvement of theories and instruments, certain phenomena, D , posited by existing theories are detectable by the extended senses, but others are not.

Thus there is no evidential basis for any extension of measurement and detection beyond D. Since this argument is applicable at any stage of any supposed extension of the senses, it challenges -- in the name of knowledge empiricism -- any extension of the senses.

Considerations such as these seem to have focused the attentions of realists on what we might call extra-experimental standards for theory assessment.

To see what these are, let's examine the EIT mentioned earlier. Why would a knowledge empiricist defend the EIT? But is anything like this right? Pretty obviously -- and pretty obviously by empiricist standards -- no.

Consider any case in which observations in some set, O , provide us with good scientific evidence to accept some theory, T , such that T applies to an range of observable cases not represented in O that is, consider any case of scientifically justified induction. In any such case there will always be infinitely many pair-wise empirically in equivalent theories such that a each of them is empirically inequivalent to T and b each of them is compatible with all the observational data ever collected.

This is just the Humean point that induction is not deductively valid. If we have sufficient scientific evidence to justify our accepting T , that evidence must justify our rejection of each of these other theories. So, there must be rational standards for the assessment of scientific evidence in addition to the standards which say that evidence for or against a theory can be provided by the success or failure of observational predictions derived from the theory.

Let's call these standards extra experimental. They solve the equation! AND, both realists and empiricists agree, they are capable of adjudicating between competing substantive conceptions of the world because they can adjudicate between empirically inequivalent theories.

So, realists and empiricists agree that it isn't true that rational standards for the assessment of scientific evidence dictate that choice between competing theories must always be based on the results of crucial experiments. Where does that leave the underdetermination argument against knowledge of unobservables?

Almost all scientific realist responses to empiricist anti-realism in the last three decades can be understood as variations on the idea that the solution to! Defenses of realism along these lines see, e. An obvious reply to the EIT is that it ignores the role of explanation as an evidential standard: perhaps one, among a family of empirically equivalent theories, is to be preferred because it explains observable phenomena better than the others, even though it makes the same observational predictions.

The standard logical empiricist treatment of explanation, the deductive-nomological account see Hempel , ; Hempel and Oppenheim , responds by identifying the explanatory power of a theory with its predictive power. Over the last several decades a great many philosophers have been critical of some aspects or other of this reduction of explanation to prediction see, e.

In the context created by this critical work, the notion of explanation, as an independent component of rational scientific methodology, has been to some extent rehabilitated. A closely related development is also important. Goodman drew the attention of philosophers of science to the important point that only some hypotheses, the projectible ones, are in the running for confirmation by observations, and that projectibility judgments are in some way or other a posteriori judgments informed by previously established theories and practices.

What has become pretty clear is that, however they are to be philosophically analyzed, projectibility judgments are in fact judgments of plausibility in the light of previously established theories Boyd ; Lipton , , and that plausibility of the relevant sort is a matter of the sort of unification with those theories which has explanatory import.

So, explanation, in its own right, and as an aspect of projectibility judgments, appears to play a crucial role in the assessment of observational evidence for scientific theories.

To a good first approximation, the following characterize the conditions under which observations, O , substantially confirm a theory T :. The basic strategy of defenses of realism which argue that the solution to! There is a very rough division between two versions of the strategy in question. One strategy, let's call it local explanationism , perhaps reflected in McMullin , ; Miller ; and Lipton involves arguing that the relevant explanation-involving, extra-experimental criteria do, in some cases, successfully adjudicate between empirically equivalent theories, so that some scientific knowledge of unobservable phenomena is actual.

An alternative approach, the abductive strategy , see, e. The justification of inductive methods in science is, therefore, provided by scientific realism, understood as itself an a posteriori scientific hypothesis. There are interesting differences between these approaches, and between the various different versions of each, but certain empiricist challenges can be raised against all or most of them.

Fine , a has offered two very significant, and closely related, criticisms of the abductive strategy.