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Preface

The relationship between philosophy and science is intricately complex and notoriously difficult to describe. This is why the zone of interaction between them is so fascinating, both for philosophers interested in science and scientists with philosophically open minds. This “in between zone” can by no means be reduced to a narrow band separating these two fields; it rather infiltrates deeply the strata of scientific research and invades many areas of philosophical analysis. It is not only that science – as a certain phenomenon – may be an object of study for philosophers. By following some especially vital strands of thought, leading through the most fundamental scientific theories or models, one reaches domains on which one cannot avoid asking the kind of questions which are traditionally reserved for philosophy, questions such as those pertaining to existence, truth or rationality. However, less ambitious but equally important problems inhabit the “interface zone”, for instance in problems related to space, time, causality and various epistemological questions. This zone is far from static; it is full of motion and truly dynamic. It is very instructive to investigate the migration of concepts between scientific and philosophical discourses and to see how these concepts change their meaning depending on their actual environment.

The volume we now offer to the Reader can be regarded as an excursion, or rather an exploratory expedition, into this “in between zone” and this constitutes a brief presentation of your companions in this risky enterprise.

The volume opens with a paper by Robert Audi, Naturalism as a Philosophical and Scientific Framework: A Critical Perspective, which tackles the problem of naturalism. After introducing some of the classical doctrines of naturalism, the author undertakes a critical analysis of scientific (methodological) naturalism, and attempts to substantiate the thesis that it does not necessarily exclude ontological pluralism. He argues further that the so-called scientific worldview does not require the assumption of the causal closure of the universe. Roman Murawski’s On Proof in Mathematics is devoted to the elucidation of the concept of proof. The author claims that one should distinguish between two different ways of understanding ‘proof’ in mathematics: the ‘informal’ one, used in the every-day practice of mathematicians, and the ‘formal’ one, developed by logicians and those working on the foundations of mathematics. The following chapter, Logical Form and Ontological Commitments by Krzysztof Wójtowicz, poses the question of what is the relation between ontology and ‘ideology’ vis a vis the problem of the ontological commitments of scientific theories. The problem is discussed against the background of various interpretations of quantifiers: it turns out that one’s chosen understanding of quantifiers influences one’s ontological commitments. Bartosz Brożek, in Neuroscience and Mathematics. From Inborn Skills to Cantor’s Paradise, provides an overview of the results obtained in the neuroscience and psychology of mathematics, and attempts to reconstruct the phylogenetic and ontogenetic history of mathematical cognition. He claims that mathematics is an ‘embrained’, embodied and embedded phenomenon. Against this background, he analyzes two classical problems connected to mathematics – mathematical Platonism and the unreasonable effectiveness of mathematics in the natural sciences.

Michael Heller’s chapter, The Ontology of the Planck Scale, is devoted to the question of how the physical theories which aim at describing phenomena at the Planck scale may be used in ontological speculation. The author’s claim is that since the Planck scale is currently the most fundamental level known to science, it should also teach us something about the fundamental ontological problems. In particular, at the Planck scale such notions as object, time, causality or change seem to be essentially different than the corresponding concepts in the classical ontologies of Aristotle, Kant or Whitehead. Wojciech Grygiel, in Spacetime in the Perspective of the Theory of Quantum Gravity: Should It Stay or Should It Go?, argues – against the background of an analysis of such research programs as the loop quantum gravity, superstring theory, twistor theory, topos theory or noncommutative geometry – that the categories of space and time, as we understand them, may play no role at the Planck scale, and hence it is most likely that those intuitive categories will disappear from the explanations of the fundamental phenomena. Helge Kragh, in The Criteria of Science, Cosmology, and the Lessons of History, considers what are the criteria which enable the distinction between science and pseudo-science. His analysis is carried out against the background of two examples: the steady state cosmology and the anthropic multiverse conceptions. He underscores the role of philosophical assumptions in the construction of both theories. The chapter culminates in the presentation of several examples of the uses and abuses of the history of science in arguing for or against particular scientific theories. The following chapter, Bogdan Dembiński’s Structuralism in Platonic Philosophy of Science, aims at substantiating the thesis that, in the eyes of a philosopher of science, Plato may be seen as a structuralist. The author begins by identifying the key aspect of Plato’s thinking, i.e. his account of the relationship between One and Many, as depicted in the dialogue Parmenides. Dembiński claims that for Plato each and every relationship between One and Many constitutes a whole, which in the contemporary terms may be called a structure. He then concludes with the description of the major features of Plato’s structuralism.

The goal of Wojciech Załuski’s chapter, On the Relevance of Evolutionary Anthropology for Practical Philosophy, is to assess the importance of evolutionary anthropology in the context of practical philosophy. The author argues that evolutionary anthropology – understood as a view of human nature implied by the findings of evolutionary psychology – is more suited to constitute an important aspect of legal philosophy rather than of moral philosophy. The main argument backing this claim is that the primary object of moral evaluation are motives, while legal evaluation pertains to actions. Łukasz Kurek in Emotions from a Neurophilosophical Perspective addresses the question of whether emotions constitute a coherent category, both from philosophical and scientific perspectives. He begins by identifying various levels of the explanation of the concepts used in folk psychology (such as emotions), and indicates that the concept of emotion is both of philosophical and neuroscientific interest. Philosophy and science provide us with two popular theories of emotions, the cognitive and the noncognitive. The author claims that they both account for some phenomena usually categorized as emotions, which leads to the conclusion that emotions do not constitute a natural kind. Teresa Obolevitch, in her chapter The Issue of Knowledge and Faith in the Russian Academic Milieu from the 19th to the 21st Century, analyses the relationship between science and religion in the Russian ecclesiastical tradition. She underscores the peculiarities of the Russian academic philosophy, and describes the development of ‘natural apologetic’ in the 19th century, as well as the 20th century conceptions of the relationship between faith and reason.

The papers collected in this volume have been written within the research project The Limits of Scientific Explanation, carried out at the Copernicus Center for Interdisciplinary Studies in Kraków and sponsored by the John Templeton Foundation. It is our hope that these contributions – even if they take on different problems and make recourse to different philosophical methods – together constitute a coherent illustration of how complex and intriguing the relationship between philosophy and science may be.

Michael Heller

Bartosz Brożek

Łukasz Kurek

Robert Audi

University of Notre Dame

Naturalism as a Philosophical and Scientific Framework

A Critical Perspective[1]

Introduction

In contemporary philosophy, naturalism is probably the most pervasive and influential intellectual orientation. It is widely presupposed; deviations from it are commonly felt to need justification; and where an important phenomenon, such as value, does not seem naturalizable, we find a plethora of attempts to show that, despite appearances, it is. Naturalism was important in philosophy even in the 19th century, but its popularity increased with the influence of certain elements in positivism and with the development of the philosophy of science. In 1969, W. V. Quine published “Epistemology Naturalized”, which helped to popularize the verb ‘to naturalize’, and ever since then the philosophical literature has had title after title announcing a naturalization of something viewed as highly significant.[2] But as common as appeals to naturalism are, its defense is rarely accompanied by a general account of the position, and it is frequently defended at best from a restricted point of view, such as that of epistemology or ethics. I am not prepared to offer a nicely detailed conception of naturalism as adequate to all of these contexts. But we can approach a plausible broad conception through reflection on how naturalization might proceed in some major philosophical territories: the metaphysical, including a focus on the mental; the epistemological; the scientific; the theological; and the ethical. I begin with some background observations; proceed to sketch an approach to conceptualizing naturalization projects and thereby naturalism as the successful completion of such a project. This will help us to see how much unity the notion of naturalism has, or can be given. A special concern of the paper is to determine what kind of naturalism, if any, is required as a presupposition of scientific inquiry.

1. The Historical and Philosophical Context

Historically, naturalism has ancient roots, perhaps most notably in Aristotle, who saw human beings as part of nature, derived an ethic mainly from what he took to be natural facts about us, and made no sharp distinction between scientific and philosophical knowledge. Aquinas’s influential rendering of Aristotle preserved certain elements in Aristotle’s naturalism, but denaturalized much of his thought, not only by making theology central and, I believe, introducing a notion of the a priori that went beyond the resources of Aristotle’s apparent empiricism, but also by putting natural laws under God and licensing, though without mapping, a supernatural route to certain discoveries about nature. 17th century rationalism, especially in Descartes, took philosophy still further from Aristotelian naturalism.[3]

Elements of rationalism remained in some of the British empiricists, at least Locke; but empiricism, especially in Hume, who carried it into semantics as well as epistemology, emerged as fertile ground both for the beginnings of modern naturalism and for the scientific worldview. Perhaps Kant may be seen as, in part, reconciling a kind of rationalism with a scientific worldview; but it was in England, particularly with J. S. Mill, and later, in America, that naturalism most prominently flourished in the nineteenth century.[4]

By the early 20th century, naturalism had strong proponents on both sides of the Atlantic and especially in America, where Roy Wood Sellars wrote, in 1922, “We are all naturalists now,” though he quickly added – quite insightfully, in my view – that naturalism “is less a philosophical system than a recognition of the impressive implications of the physical and biological sciences.”[5] Wilfrid Sellars, writing three decades later, went further. Parodying Protagoras, he said that “science is the measure of all things, of what is that it is and of what is not that it is not.”[6] And in a famous paper defending materialism about the mental, J. J. C. Smart had no hesitation in saying “That everything should be explicable in terms of physics (...) except the occurrence of sensations seems to me frankly unbelievable.”[7] He apparently intended ‘everything’ to apply unrestrictedly, but even excepting such abstract entities as numbers would make him a naturalist about what is commonly called the world.

20th century naturalism may have arisen initially as a reaction to supernaturalism, which posits beings or (concrete) entities that are neither in the physical world nor (assuming existence is possible for what is not in the physical world) necessarily physical or material at all. So conceived, naturalism stresses a non-theistic approach to understanding the world and, typically, scientific ways of explaining events. Modern empiricism is also a factor: its adherents see both meaning and knowledge as arising from our experience of the natural world in a way that makes it easy to conclude that the truths about nature are the only basic truths there are. 20th century positivism, though it refines this view, retains its naturalism: for positivism, observation and scientific method are the only grounds of substantive knowledge (knowledge of logical and analytic truths is not considered substantive on this approach).

Early in the 20th century, naturalism was often clarified by contrast with two major philosophical views. First, naturalists in philosophy opposed idealism–roughly, the theory that reality depends on, or is indeed constituted by, minds and their ideas. Second, and perhaps even more important, naturalists opposed ethical views that posited intrinsic value, such as that of the dignity of persons, as an irreducibly non-natural phenomenon. The rightness of an action, on these views–Moore’s for instance–is a moral property that cannot be reduced to (e.g.) any naturalistic property, such as the total pleasure the action produces. On Moore’s view, pleasure has intrinsic value, but is not equivalent to the intrinsically good.[8]

More recently, naturalism has been contrasted with Cartesian dualism and interpreted in relation to the possibility of an ultimately physicalistic understanding of human behavior. We are flesh and blood, neurons and synapses; and if the life of the mind is more than a powerless shadow, it must occur in this biological network. In the past three decades, naturalism has also become a powerful force in the theory of knowledge and justification. Knowers are seen not as meeting evaluative standards, such as criteria that entitle one to believe, but as reliable instruments responding to experience of the world: they reliably register truth rather as a good thermometer registers temperature.

In metaphysics, then, we have naturalism both as a reaction to supernaturalism and as a rejection of mind-body dualism such as we find in Descartes; in ethics, naturalism–at least in realist, as opposed to noncognitivist versions–appears as a rejection of irreducible notions of value and rightness (and an effort to naturalize the corresponding properties); and in epistemology naturalism accounts for knowledge and justification in terms of notions amenable to scientific treatment, particularly the concepts of physics and psychology. If there is a unifying conception of naturalism in all these domains, it is at least not commonly made clear. One could, for example, be a naturalist in rejecting transcendent beings, but a non-naturalist in the philosophy of mind, ethics, or epistemology. Indeed, it may be that, in any one of these domains, there are forms of naturalism that are consistent with rejecting naturalism in all the others. If, however, we recall Sellars’s claim that science is the measure of all things and Smart’s view that everything is explicable in terms of physics, we may think of philosophical naturalism as, in outline, the view that nature is all there is and the only basic truths are truths of nature. This is certainly not the only kind of naturalism that merits the term ‘philosophical’, but it represents a strong, broad thesis that serves as a good focus for analysis and comparison.[9] We can gain a better understanding of naturalism so conceived–that is, as a broad metaphysical thesis–and of departures from it by considering some of the projects philosophers regard as advancing it.

2. Scientific Naturalism

Many philosophers of science today hold or presuppose some form of philosophical naturalism. But are scientists as such committed to any form of it? Here we should scrupulously observe the distinction between philosophical naturalism and methodological naturalism. Methodological naturalism–which, unlike the former, is not a metaphysical position–is, roughly, the view that causes and explanations of natural phenomena should be sought in the natural world, paradigmatically in terms of what meets at least three commonly endorsed criteria for a scientific theory–testability, publicity, and empiricality (these are taken to be important necessary conditions, not sufficient conditions, though a case can be made that there is an interpretation of them on which anything satisfying all three and deserving the name ‘theory’ would be scientific). Methodological naturalism requires conducting scientific inquiry in what might be called descriptive natural categories and with testability and the experimental, public, predictive character of science in mind; but it does not imply a comprehensive ontology nor even deny the existence of anything supernatural. Indeed, methodological naturalism is not fundamentally descriptive at all; it is prescriptive, a normative (though non-moral) claim about scientific inquiry. It is clearly consistent with Roy Wood Sellars’s contention that naturalism is “a recognition of the impressive implications of the physical and biological sciences.” This contention does not imply full-scale philosophical naturalism, even if for some thinkers, especially those who are pragmatically inclined, they make it attractive.

Naturalism and the drive for intellectual economy

It must be granted that naturalism as I have characterized it (and also as it is usually described) is no clearer than the notion of the natural, but a standard assumption is that the physical is paradigmatically natural and, to take the strongest contrast, that God as understood in any major monotheistic religion is supernatural. The elements of scientific method I am emphasizing are methodological, not ontological. As such, they are neutral with respect to the possibility of supernatural agency, and methodological naturalism neither affirms nor denies theism. Neither the testability nor the publicity nor the empirical character of scientific hypotheses entails any substantive ontological conclusion, such as the thesis that only natural events can be causes or that there cannot be an infinite chain of causes extending into the past.

It is, however, commonly and plausibly held that a commitment to scientific method presupposes a commitment to some form of Ockham’s Razor, understood as a principle calling for intellectual economy. Does this principle favor philosophical naturalism–or at least the anti-supernatural elements in it–over methodological naturalism, which is neutral with respect to theism? The question is not easy to answer. On analysis, the status of Ockham’s Razor is not altogether clear. On any interpretation, it implies that other things equal, the simpler of two competing views is preferable. Suppose this is our working formulation. Isn’t philosophical naturalism a simpler worldview than, say, a theistic one that is otherwise as much as possible like, say, the scientific realism that a philosophical naturalist could countenance? Answering this requires some account of simplicity, an elusive notion I cannot take time to explicate.[10] Still, if we take it that the number of basic assumptions and irreducible kinds of entities posited by a worldview is most important for determining the degree of its simplicity, then we might suppose for the sake of argument that there is some reason to think that the naturalistic worldview is simpler than a theistic view.

Suppose the naturalistic worldview is simpler than any plausible theism. Some philosophers would stress that it still provides no answer to the classical cosmological question, Why is there something and not nothing? If it does not, and theism does, then other things are not equal in the comparison between, on the one hand, a theistic worldview combined with methodological naturalism and, on the other side, philosophical naturalism. And, for many lives, philosophical naturalism does not accommodate the most plausible explanations for certain religious experiences or, indeed, for some people’s long-standing patterns of religious experience. Either of these points may well suffice to outweigh even differences in simplicity greater than those that may exist between a classical theistic worldview and naturalism.

In the light of these points, I doubt that Ockham’s Razor–understood as the principle that in framing and adopting explanations and theories, we should prefer the simpler, other things equal–cuts deeply against a classical theistic worldview as such. Note that the principle does not say, and in my view should not be taken as entailing, that it is irrational to hold a view while aware that an alternative that is otherwise as plausible is simpler. Rational preferability of one view over another does not imply the irrationality of holding the (perhaps marginally) less desirable view. As to preferability, we should consider at least two kinds that bear on comparing hypotheses and worldviews.

Two conceptions of the Razor as endorsing preference for the simpler

So far, I have spoken as if it were clear what the status of the Razor is.[11] But it is not. Once this is seen, the bearing of the principle on the preference for a naturalistic worldview can be clarified. The principle is most widely considered epistemic, in the broad sense that it provides an evidential standard relevant to assessing the candidacy of a belief, hypothesis, or theory for justified belief or for knowledge or for both. It also applies to acceptance as a propositional attitude or to hypotheses as candidates to be objects of any kind of epistemic attitude. To assess this principle, we should take account of two major approaches in epistemology, internalism and externalism. Accordingly, we must distinguish internal from external epistemic considerations: roughly, between justificatory elements–evidences, in a sense–that are accessible internally, i.e., to reflection or consciousness, and, on the other hand, objectively truth-conducive factors that are not thus accessible.[12]

May we (other things equal) take the simpler view to be better justified, on internal grounds? This may seem obvious. It is not. What may be obvious is something easily conflated with the principle conceived epistemically: namely, the quite different principle that, other things equal, it is preferable to work with a simpler view in constructing a theory or in framing or retaining a worldview. There is less to deal with–to explain, to connect with other elements, and so forth. That interpretation, however, yields a practical principle that could be true even if there were no difference in evidential status between more and less simple views. Call the practical principle in question the principle of least effort. It might also be called the principle of optimal efficiency to emphasize that it opposes expending more effort than is needed for one’s governing purpose.

This principle of least effort may be self-evident, and it is plausible from an internalist point of view (at least partly on the a priori basis of understanding alone); but it does not entail the Razor principle as stated epistemically and understood internalistically. A hypothesis that is easier to work with is not thereby better evidenced, say in terms of confirmatory experiences or predictive power, than an otherwise equally well confirmed alternative.

A return to the Razor principle is considered to be epistemic: roughly, the principle of the greater likelihood of the simpler hypothesis. We have seen no reason to endorse it from an internalist point of view. Do we have reason to think that from an external perspective, simpler views are more likely to be true? Perhaps, for some plausible notion of simplicity, we do, given common experience and the track record of scientific hypotheses. The intuitively simpler hypotheses have apparently tended to be better confirmed (though this might be at best hard to show owing to the difficulty of separating considerations of simplicity from those of degree of confirmation). I do not see how to demonstrate this, though doubtless we might entertain an evolutionary explanation. The preference for simplicity could have fitness value: perhaps, since we do in fact generally prefer simpler hypotheses, we probably would not have survived, or at least survived and reached the level of efficiency we have achieved, if the ways of nature were not better evidenced by simpler hypotheses.

It is important to see why this evolutionary hypothesis provides at best limited support. First, it does not entail the truth of the Razor principle understood epistemically. Second, it presupposes that we have perceptual knowledge or at least true perceptual beliefs in the first place, in which case the question whether simplicity enters into those notions would have to be addressed before that justification could be considered to be sufficiently independent of simplicity to support the Razor without a vitiating circularity. Such inductive reasoning in favor of the Razor taken epistemically also provides only an empirical justification. I propose simply to assume that nature is (other things equal) better described by simpler hypotheses and thus to grant that the Razor may have at least external evidential force. What might explain why it does–why nature’s ways are better evidenced, in terms of objective probability, by simpler hypotheses?

Another possibility is that nature might be designed to be understood and predicted by beings like us who prefer simpler hypotheses.[13] I see no way to show that this (presumptively theistic) explanation is correct, but naturalists should not simply rule it out of hand, particularly since there need be no conflict between a theistic worldview and a deeply scientific habit of mind. The world can be studied with as much scientific rigor by those who believe it is divinely created as by those who think it is a fortuitous precipitate of blind forces.

3. Ontological Pluralism

So far, we have seen no decisive reason to think that a scientific habit of mind requires commitment to philosophical naturalism, as opposed to an ontologically more pluralistic worldview. For some highly scientific people, however, including those who are theists, methodological naturalism is a possible position–even a comfortable position. We have also seen no decisive reason to consider theism clearly less plausible than atheism given a commitment to Ockham’s Razor. Even if it is less simple in some way, it does not follow that it is less well evidenced. Ontological pluralism, at least of a kind affirming the reality of both natural and non-natural entities, seems a plausible position. To be sure, it should be emphasized that even a kind of materialist ontology is compatible with a theism on which God is embodied in matter–as possibility that also seems open, however unorthodox it may be.[14]

Abstract entities

A full-scale materialist ontology must also discountenance abstract entities. This is a prospect I cannot pursue in detail, but philosophical naturalists are in any case more concerned with naturalizing any reality with causal power (as supernatural beings are thought to have) than with naturalizing the abstract, which is typically considered to be outside the causal order. Abstract entities are a kind of annoyance to some naturalistic thinkers, since they must be accounted for in a comprehensive ontology; but if they have no causal power, they at least do not do anything in the natural world and cannot compete with scientific explanations or undermine scientific predictions.

Monistic naturalism–the kind countenancing only one basic ontological category, such as the physical–seems to me quite implausible even as applied only to bearers of truth value. If, for instance, they are propositions, or even sentence types as opposed to sentence tokens, then there are some abstract entities.[15] Sentence tokens can be argued to be physical–at least if we can plausibly take mental tokens of sentences to be physical–but sentence types of the kind represented by what is common to two printings of the same article–are not plausibly viewed as physical. This is not to suggest that we should not avoid positing abstract entities, other things equal–as Ockham’s Razor on any plausible interpretation would counsel. If sentence types could do the work of propositions and the former are unavoidable posits, then we could treat talk of propositions as a mere convenience. But sentence-types are also abstract. Still, neither posit necessarily affects scientific inquiry; if scientists do not find proposition talk burdensome–or prefer it to sentence talk as less likely to result in ambiguity–philosophers should feel no need to discountenance propositions on the ground that positing them is at odds with good scientific practice.

Universals and numbers present other challenges, but there, too, I must be content simply to point out the obstacle to full-scale materialism rather than argue for commitment to pluralism that includes the abstract. Suppose, however, that there are apparently properties that are not even descriptive–and in that minimal sense natural–to begin with. Then there would seem to be a twofold problem for a thoroughgoing naturalism: first, to eliminate the normative element; secondly, to eliminate the abstract element. Here, I will concentrate only on the first problem and then only in the general way appropriate to a broad essay of this kind.

The normative domain

Supposing there are normative properties–which, to be sure, noncognitivists deny–can reductive naturalists accommodate them? The Cornell Realists have attempted to give a kind of reduction here, but I have elsewhere argued that although we might regard them as providing reasons to think moral explanations can be naturalized, they have not shown that moral properties are naturalizable.[16] Briefly, the idea is that when a moral property, such as the injustice of a regime, is cited to explain behavior, say a revolt against that regime, the explanatory work is done by some grounding property that is natural. For instance, wherever injustice can be justifiedly and correctly cited as explaining a revolt, the person giving the explanation must be justified and correct in taking to be present such grounds of injustice as police brutality and virtually confiscatory taxation (say approaching ninety percent), and these are natural phenomena that can explain a revolt in terms of social-scientific generalities that do not require normative concepts in their content. Moreover, if we did not take injustice to imply the presence of such plainly causative elements, we would not see how it explains the revolt. It does not brutely explain that, even in the way releasing a soccer ball in midair might brutely explain its falling. We can detail, and must be able to detail at least by specifying grounding elements, how normative ascriptions succeed in explaining what they do explain, in a way we need not be able to do this for the dropping ball or, in the psychological case, for the normal raising of a hand, given the agent’s decision to raise it.

There is, however, another route to possible naturalization of the normative. Suppose for the sake of argument that we can formulate a disjunction of all the grounds of moral obligation. If W. D. Ross’s famous list is as comprehensive as he hoped, we could say that an act is obligatory (for a person) if and only if (in rough terms) it is either a doing of justice (in the descriptive sense of treating persons equally), an avoidance of injury, a promise-keeping, an avoidance of lying, a beneficent deed, an act of self-improvement, a reparation for injury, or an expression of gratitude. One could do the same kind of thing in epistemology, for instance holding that a belief is justified if and only if is grounded in either perception, or memory, or introspection, or reason, or testimony. Even if these biconditionals are not analytic or any kind of conceptual truth,[17] might they suffice for reduction of the normative properties in question to descriptive properties?

Property identity as an element in ontological reduction

To answer this, we must at least assume that the equivalence is necessary. But may we take necessarily equivalent predicates to express the same properties–identical properties? This is doubtful. Consider the property (possessed by every other integer) of being even. Is this the same property as that of being a member of the series 2, 4, 6, 8, etc.? The property of being even (being an even integer) is equivalent to the property of being divisible by 2 without remainder; but is that property identical with, or even equivalent to, the property of being a member of the set 2, 4, 6...? The members of the set in question are thus divisible; but is being a member of it the same property as being divisible by 2 without remainder? The former is a set-theoretical property, the latter a numerical (arithmetical) one. These seem different in kind.

This example and others, such as those involving purported reductions of normative concepts or properties, bring out an important point. The relevant sense of ‘reduction’ is no clearer than our understanding of when two predicates express the same property (or, given any properties F and G, under what conditions F = G). This remains a vexed question. Do two predicates express the same property provided they are (a) synonymous, (b) analytically equivalent, (c) conceptually equivalent (if that is not equivalent to one of the other categories), (d) logically equivalent, (e) metaphysically equivalent, (f) synthetically a priori equivalent, (g) explanationally equivalent, (h) nomically equivalent, (i) causally equivalent, or (j) something else again? Even if we have an answer to this question, the ten notions in question remain controversial, and they all need analysis.

Whatever our criteria for property identity, it is far from clear that there are disjunctive properties at all, as opposed to disjunctions of predicates that each express a property. If there are disjunctive properties, we need an explanation of why specifying that a shape is either circular or elliptical is not an answer to the question ‘What are its shape properties?’ or, especially, ‘What is its shape?’ One could argue that the needed explanation is simply pragmatic, say that in asking for a shape we presuppose in normal contexts that a non-disjunctive specification will be given; but that is not confirmed by our explanatory or descriptive practices even when answering a particular question in a communicative situation is not a requirement for appropriateness.[18]

To be sure, the disjunctively specified grounds of obligation cited above are significant; they yield multiple paths from certain descriptive notions to the crucial notion of obligatory action. Similarly for the grounds of justification, which might be argued to be disjunctively specifiable in terms of, say, the classically recognized basic sources of justification: perception, memory, introspective consciousness, and intuitive reason. But this point about the grounding of the normative shows–assuming the grounds in question are genuinely constitutive–only that the normative properties (and the concepts of them) are anchored in the natural world, not that those properties are genuinely natural or even equivalent to disjunctive properties, if there are such properties.

This is a good place to note that what has been said of properties may well not apply to concepts. Concepts are essentially connected with subsuming things under the abstract equivalent of a description, an equivalent that may be disjunctive or otherwise compound. This does not require indicating something about what the relevant things are “like”, especially where this is related to explanation, prediction, connections to other things, or all of these (and perhaps other elements). Viewed in this way, at least, concepts may be seen as disjunctive. In this, and in the very fine-grained way in which we individuate them, concepts are more like propositions than like properties.

One might now wonder whether we might naturalize normative concepts like that of obligation disjunctively, even if not the property. First, it is doubtful that a naturalistic concept can express a non-naturalistic property. If this is so, then conceptual naturalization of the normative will apparently fail if naturalization of normative properties fails. But even apart from this question, the concept of obligation is surely not equivalent to the disjunctive concept of being either a promise-keeping or an avoidance of harm or... for any purportedly complete list of the constitutive sources of obligation. These elements may perhaps indicate all of the various grounds of obligation but not what, conceptually, obligation is. It is a kind of commitment, and the disjunction indicates ways of incurring it, but not what it is.

4. Non-Reductive Naturalism

The view that non-natural properties are strongly supervenient on natural ones is sometimes called non-reductive naturalism, and the name is doubly appropriate if the supervenience is paired with a grounding relation. It normally is paired with one, though in the mental-physical case the grounding relation is empirical and presumably nomic, whereas in the normative case it is (on my view and that of many others) a priori and metaphysically necessary rather than nomically necessary. Such naturalism is, however, clearly a liberal naturalism: although it may embody a denial of substance dualism–a view that liberal naturalists reject–it is consistent with property dualism, since even the strong grounding relation obtaining in the normative cases does not imply the possibility of reduction of the normative to the natural. The point is not that grounding is not a reductive relation, though that is true and important; the point is that this character of the relation does not imply the impossibility of reduction of the grounded properties to some property of the kind to which the grounding property belongs, in this case natural properties.

It should be added that so-called non-reductive materialism as so far described is even consistent with Cartesian dualism. If mental properties are grounded in (but not reducible to) physical ones–the kind of natural property important for naturalism in the philosophy of mind–then the mental properties can be in a different category, perhaps being properties of a Cartesian mental substance. To be sure, mental-physical causal relations may be less easy to understand given that picture, but nothing in the concept of causation precludes cross-categorial causal relations. I would stress, however, that people who hold non-reductive naturalism would generally restrict mental properties to properties of embodied beings and would not countenance Cartesian mental substances. One metaphysical problem, of course, is how to understand mental properties as at once not reducible to physical ones yet necessarily belonging to physically embodied beings.

Even if mental properties are not themselves physical, psychological science can proceed as it would if they were physical. If, for instance, there are lawlike connections between, on the one hand, sets of desires and beliefs and, on the other hand, actions, these can be studied either (a) psychologically in relation to objective criteria for applying the relevant psychological and behavioral predicates or (b) neurophysiologically in terms of the grounding properties and their role in producing either the psychological states or the physical movements those states explain, or both. For the normative counterpart of non-reductive physicalism, the point is different, since some of the generalizations in question, say that failure of the prosperous to do any beneficent deeds is wrong, are not empirical. But some of the generalizations are empirical–say that injustice breeds anger–even if the empirical work, and hence the task for social-scientific appraisal, is at the level of the grounding properties. If ethics is not itself a science, there is certainly a host of scientific questions about the conditions for its realization in human conduct, the risks to its grip on human motivation, and the identification of those for whom it yields guiding standards–moral individuals–and those for whom it does not.

It is the metaphysician, not the scientist, who tends to feel a need to reduce non-natural properties to natural ones. There is no reason to object to the quest and much to be learned from appraising its degree of success. But, as a philosophical framework appropriate to a scientific habit of mind and supportive of the progress of science, methodological naturalism is as strong a naturalistic position as required.

5. Realist and Anti-Realist Naturalisms

I have already suggested that eliminatism regarding abstract entities is implausible and that there is no need for it on the part of scientific investigators. But I have also suggested that normative properties do not have causal power, even if their presence can explain certain facts, as where people’s lying and cheating explains why they are immoral. Let us explore the significance of these points for a representative kind of normative property, the moral.

Moral epiphenomenalism and ethical noncognitivism

Suppose that moral properties are not causal. This does not imply that they are epiphenomenal. Their instances are not effects of instances of the properties that ground them: instead, the former instances bear a consequential relation to those grounding instances. Being an instance of a lie does not cause being an instance of prima facie wrongness; it conceptually entails it. If wrongness is not an effect (strictly, an effect-property), it need not be epiphenomenal: indeed, on my view it is not even a candidate to be so. Epiphenomena are elements that figure in the causal order as effects (or effect properties) but abruptly–and, some would say, inexplicably–terminate a causal sequence.

The most plausible conclusion to draw here is probably that moral properties and concepts do not function, or do not mainly function, in the causal order, at least as causal elements therein. Nonetheless, it is in part because some philosophers believe that moral properties do not have causal power that they want to eliminate them.[19] Perhaps many naturalistic philosophers believe or presuppose that to be is to be the value of a causal variable. If moral properties lack causal power, can they be eliminated?

This is an indirect way of raising the question whether noncognitivism in ethics and other normative disciplines is successful. I do not see that it succeeds, but there remains a great deal of controversy about this. Perhaps the best argument for the view, an argument provided originally by Hume in the Treatise, proceeds from the premise that moral judgments, but not cognitive (“descriptive”) ones are intrinsically motivating. I can agree that non-normative (roughly, descriptive) judgments are not intrinsically motivating, but I have argued (as have many others) that moral judgments are not either.[20] Rather than pursue this complicated issue, I prefer to indicate how my own ethical theory can accommodate elements of naturalism.

Moral realism in the intuitionist tradition

My strategy in metaethics–now called “the New Intuitionism”,[21]–has not been negative even in containing a critique of noncognitive analyses. Instead, I have proposed a moderately rationalist intuitionism which anchors moral properties in natural (descriptive) ones, as with the list of grounding properties from Ross (to which I have added two others[22]). This is a realist view, but does not require reducing normative properties to descriptive ones. Here I want simply to indicate that even if one could show that moral properties are natural, the major elements in my theory would be sustainable: the theory accords well with, but does not depend on, a non-naturalist account of normative properties. As is well known, G. E. Moore held that normative properties are non-natural. My intuitionism does not presuppose this. The most important point here is that the epistemic status I attribute to intuitive prima facie duty principles–being necessary and a priori–does not require that the properties figuring in those principles be non-natural.[23] Nor is that incompatible with or entailed by the thesis that moral properties are, as Moore, Ross, and other intuitionists also hold, consequential on natural ones. This neutrality toward Moorean non-naturalism is an advantage in making a version of intuitionism eligible for endorsement by many contemporary moderate naturalists, certainly including liberal naturalists.

If it turns out, then, that moral and other normative properties are natural, my view does not require either changing my position on what properties ground them–these are natural properties on the present account–or moving to anti-realism, or altering the relation I have described above between ethics and science. Nor need the moral epistemology be revised. The relation between moral and non-moral properties and concepts can have the character I have maintained whether or not those properties are natural. The metaphysical change from neutrality toward naturalism to endorsing some version of it would leave both the normative content and the epistemology of the view essentially unchanged.

Noncognitivism is only one of many anti-realist positions. Not all of these are motivated by philosophical naturalism. Eliminativism in the philosophy of mind might be, since it discountenances mental properties in favor of mental predicates somewhat as occurs in ethical noncognitivism with moral properties and moral predicates, and it seems motivated largely by the sense that the physical is what is fundamentally real. But with eliminativism in the philosophy of mind we have an error theory, on which it is simply a mistake to hold that there are, for instance, beliefs. By contrast, ethical noncognitivism does not take moral claims to be truth-valued, hence does not view them as invariably erroneous. Scientific anti-realism is not motivated by taking theoretical entities to be, like irreducibly normative properties, inappropriate to be countenanced by naturalism or, so far as I can see, even by a physicalist interpretation of reality. The position is apparently motivated by Ockham’s Razor and considerations internal to the task of understanding scientific explanation. In any case, in concluding this essay, I propose to consider a larger issue concerning the overall conception of the universe required by science as compared with the conception favored by philosophical naturalism.

6. Scientific Naturalism and Causal Closure

For thoroughgoing philosophical naturalists, although it is not an a priori truth that mental properties depend on physical ones, the physical has a kind of metaphysical sovereignty. One manifestation of this sovereignty concerns causal power–an element that, on any plausible metaphysics, entails ontic reality on the part of anything that possesses it. Let us begin with that.

Causal closure and the explanatory exclusiveness of the physical

For naturalism the causal power of mental properties must depend on that of some physical property at their base: even overdetermination by the joint power of physical and mental phenomena seems ruled out, or at least appears to be beyond the pale for a robust naturalism, which seems committed to a causal closure thesis on which all causes are physical, where this is understood to rule out that mental causes, unless identical with physical ones, can even be overdetermining causes of any effect. The view leaves open that effects of physical causes may be non-physical, since, if they are epiphenomenal, they might be merely ontologically an annoying dangler, but otherwise innocuous. Still, if a mental property has causal power, then on the closure thesis just stated, it is reducible to a physical property.[24]

This closure thesis may seem to be supported by the idea that physically identical worlds must be mentally identical. For it may appear that the only explanation of this plausible idea is either that mental properties are physical or the mental as such has no causal power. But that is not so; non-reductive materialism, especially if it embodies the idea that mental properties are grounded in physical ones, suffices to explain the idea. Consistently with that, however, is the not implausible view that every mental event has a description under which it is physical–a view that leaves open the relation between mental and physical properties. Taking the two together, some philosophical naturalists might hold that a mental event “as such” has no causal power.[25] Must a scientific naturalist hold this, however? It is one thing to require a physical ground as a platform for the causal power of the mental; it is quite another to maintain that only the physical has causal power.

We should ask, then, how important it is for a scientific naturalism to embrace the causal closure of the physical world, as opposed to its causal sufficiency, which constitutes a kind of causal plenitude: roughly, the existence of a physical nomically sufficient condition for every physical event. Causal sufficiency would assure the possibility of a comprehensive physical science. All physical events (including mental events, at least if mental properties are themselves physical) would be physicalistically explainable: roughly, explainable by citing (under an appropriate description) the instantiation of a physical property and in that sense explainable in physical “terms”. On a stronger causal sufficiency view, all natural events–which would include any mental events in the natural world–would be physicalistically explainable. But even adding this clause would not yield an implication that mental events have no causal power. Let us explore the causal sufficiency view further.

Causal sufficiency and the unity of science

Suppose that every physical event is explainable by appeal to a law of nature. We still cannot assume that there must be a way to unify our laws–a possibility that, for most naturalists, represents an ideal–or even a way to produce intuitively appealing or technically useful theories. Ontological constitution of the world is one thing; its pattern of laws is another–nor does its even being governed by laws clearly follow from the nature of its constitution alone. Even if we assume that there are no naturalistically inexplicable physical events, causal closure by itself does not guarantee those scientifically desirable results–especially overall unification of laws. Causal sufficiency, by contrast, even in the strong form, would not be exclusive in the way causal closure is.[26] It would not, for instance, rule out mental properties as such having a measure of causal and explanatory power, in a sense implying that an event’s having a mental property is sufficient for citing that event (under the relevant mentalistic description) to explain certain other events, such as actions.

To see a major difference between causal sufficiency in either form and causal closure, consider their relation to theism. Both forms of the sufficiency view are consistent with the possibility of one kind of supernatural causation. I do not mean the possibility that, at some point in time, God (or some god) created the universe with its laws and initial events, so that divine creation–which may be viewed as a kind of originative causation–in a sense underlies all causation, and each cause is a link in a causal chain tracing to creation at its origin.[27] For in that case the initial event in each causal chain would not have a natural cause. But I am including both the possibility of divine conserving causation of the universe from eternity (in which case there is no originative causation) and also the possibility of overdetermination in which a supernatural event, such as a divine volition, is sufficient, as is some natural event, such as a neural one, to produce another natural event, such as a sudden recovery of eyesight.

This is not to suggest that, on the sufficiency view conjoined with the view that there is supernatural causation of some natural events, every mentally caused natural event is overdetermined. Why, however, should it matter to a scientific conception of the world that divine overdetermination–a kind of contemporaneous co-causation–could occur? So long as there are appropriate natural laws and natural antecedents of an event, it admits of scientific explanation under some description. One can leave open whether an explanation by appeal to events under mental descriptions is scientific.[28] No explanation adducing an event in the infinite chain of causes (as would be any causal explanation of an event) will be ultimate, but that should not be objectionable. Neither the attempt to reduce mentalistic explanations or properties to naturalistic ones nor the search for ultimate explanations is required in the scientific enterprise, and the latter seems characteristically forsworn.

Now consider the status of the scientific enterprise if the causal closure principle is true and every event is caused by another event. Then (on plausible assumptions about the temporality of causation) there will be an infinite series of events extending infinitely into the past. Moreover, no physical event, including the Big Bang (which I here assume occurred), escapes the need for–or at least the possibility of explanation in terms of–a further event. We must certainly find a causative or other explaining event if we are to understand the Big Bang nomically.

A different option is to countenance substance causation as an irreducible kind of causation, or to take causal closure to be simply the negative principle that the causes of natural events are never non-physical and then allow that some causes are themselves uncaused. We can then avoid the infinite past consequence. But now the cost of causal closure would be choosing between, on the one hand, positing some brute natural event, such as a big bang, so that we have no explanation of it, and, on the other hand, a kind of regress-stopping causation (substance causation) that contemporary naturalists (among others) have seldom if ever thought they understood. Naturalists tend to consider the idea that a substance simply causes an event, such as the Big Bang, at best deeply puzzling. And what natural substance could have such a momentous issue? One thinks here of an unmoved mover with power approaching that of the divine. But for naturalism, it cannot be God. Why, in any case, would either positing a brute natural event or substance causation be preferable for naturalism to countenancing an infinite regress? That regress, however, provides for no ultimate explanations and leaves the cosmological question (Why is there something and not nothing?) unanswered and–apparently–unanswerable? Even many naturalists may find the cost of the former alternatives too great.

Causal overdetermination

If all this is so, there is some reason to look again at the possibility of non-natural causal events overdetermining some natural events, or at least originatively producing them. In any case, it is the philosophical naturalist, not the scientist, who must resist the possibility of such overdetermination. The causal sufficiency of the physical–as a principle of plenitude taken to entail the existence of physical causally sufficient conditions for every natural event–implies the possibility of as comprehensive a physical science as we can reasonably develop and is consistent with a plausible version of methodological naturalism and even with some versions of philosophical naturalism. We can either rest content with a big bang or, in principle, search further for an adequate nomic account of the facts to be explained. But unlike the causal closure principle, the causal sufficiency view does not rule out supernatural causation.

Some philosophers will be uncomfortable with one implication of the sketch so far suggested as a possibility. If overdetermination of the kind in question is possible, we might have to allow the possibility that if, say, the physical cause of a natural event had not occurred, the event would still have occurred. But this need only be a logical possibility; there need be no nomically or causally possible world in which it occurs. Scientists depend on laws of nature, or at least on causal regularities, for their explanations in any case. Why must it disturb scientists, as opposed to certain philosophical naturalists, if, in other logically possible worlds (and these worlds may even be nomically or causally impossible), a phenomenon does not admit of the kind of explanations they seek?

I have in some places spoken as if determinism is true. But I have not presupposed it (and doubt that it is true). If it is not, then causal sufficiency does not require deterministic causes of all natural events. In that case, however, there may be a type of event which is of the right kind to cause a further event, but does not always do so. Suppose such a potentially causative event is present and, relative to the natural order, it is indeterminate whether the effect will occur. Its occurrence and its non-occurrence are both consistent with the laws of nature. If the situation is such that we could correctly explain the effect by appeal to the event if the event occurs, then we might also say that God’s volitional action could occur in such a way as to “close the gap,” but without either undermining or predetermining the connection between the non-deterministic cause and its effect. This is a presumptive case of overdetermination occurring in a non-deterministic causal chain in the natural world. Whether it occurs and, if so, how often, is a contingent matter. Determinists would of course reject the conception of nature that allows this phenomenon; but determinism is not a necessary truth, and (so far as I know) there are plausible theories in quantum mechanics that are commonly taken to provide reason to consider determinism false.

* * *

Philosophical naturalism can take many forms and is motivated in somewhat different ways by different theorists and in different subfields of philosophy. In its domain-specific forms, it is more plausible in some domains of inquiry than in others. Naturalization in the philosophy of mind, for instance, seems less difficult to defend than full-scale philosophical naturalism requiring a nominalistic account of all apparent presuppositions of the existence of abstract entities. Moreover, even within a single field, such as epistemology, some core notions, say knowledge, seem more amenable to naturalization than others, such as justification. In its strong forms, naturalization can be rationally resisted without extravagant metaphysical or epistemological claims. Moreover–and this is a more important conclusion for this paper–scientific rigor does not require a commitment to comprehensive naturalism, nor is any stronger naturalism than a methodological version required for cultivation and maintenance of a scientific habit of mind. We have also seen reason to think that a scientific worldview is neutral with respect to the causal closure of the world. Causal sufficiency would suffice as a metaphysical view that accommodates the ideal of unifying science under physical laws, though that ideal itself is not one that must be endorsed by inquirers in the special sciences. It appears, then, that neither science nor ethics nor logic and mathematics, nor philosophy itself, requires endorsing a full-scale philosophical naturalism for success in providing plausible theories of human experience.[29]

Zapraszamy do zakupu pełnej wersji książki

Footnotes

[1] The publication of this paper was made possible through the support of a grant “The Limits of Scientific Explanation” from the John Templeton Foundation.

[2] Epistemology Naturalized appeared in Quine’s collection, Ontological Relativity and Other Essays (Columbia University Press, New York 1969). For discussion of this and other versions of naturalism in philosophy, see Philosophical Naturalism, “Midwest Studies in Philosophy” 1994, vol. XIX, where we find Autonomy Naturalized by Marina A. L. Oshana, among other defenses of one or another naturalization project. The papers by Laurence BonJour, Richard Foley, Richard Fumerton, Richard Grandy, and Peter Hylton all have special relevance to appraising Quine’s naturalism. See also David Papineau, Philosophical Naturalism, Blackwell, Oxford 1993. Recent treatments are found in M. De Caro, D. Macarthur (eds.), Naturalism in Question, Harvard University Press, Cambridge, Mass. 2004; S. Goetz, C. Taliaferro, Naturalism, William B. Eerdmans, Grand Rapids 2008; and D. Bradden-Mitchell, R. Nola (eds.), Conceptual Analysis and Philosophical Naturalism, MIT Press, Cambridge, Mass. 2009.

[3] Spinoza is more difficult to locate in relation to naturalism than Descartes and Leibniz and might be argued to have, or at any rate make room for, a substantial naturalistic element.

[4] One should, however, note Comte and other French figures important in the history of positivism.

[5] Quoted by Hilary Kornblith in Naturalism: Both Metaphysical and Epistemological, „Midwest Studies in Philosophy”, vol. XIX, no. 4, p. 50. Sellars was of course overlooking G. E. Moore and other non-naturalists in early analytic philosophy. Cf. Barry Stroud’s comment, “‘Naturalism’ seems to me . . . rather like ‘World Peace’. Almost everyone swears allegiance to it, and is willing to march under its banner. But disputes can still break out. . . And, like world peace, once you start specifying concretely exactly what it involves . . . it becomes increasingly difficult to reach and to sustain a consistent and exclusive ‘naturalism’.” See The Charm of Naturalism, [in:] M. De Caro, D. Macarthur, op.cit., p. 22.

[6] W. Sellars, Empiricism and the Philosophy of Mind, [in:] idem, Science, Perception and Reality, Routledge and Kegan Paul, London 1963, p. 173 (originally published in “Minnesota Studies in the Philosophy of Science” 1956, vol. 1).

[7] J.J.C. Smart, Sensations and Brian Processes, “Philosophical Review”, 1959, vol. LXVIII. The “frankly” here suggests a high level of conviction and also that he realized he was not able to provide a conclusive case for the mental-physical identify thesis.

[8] For a detailed examination of Moore’s metaphysics of value see P. Butchvarov, Skepticism in Ethics, Indiana University Press, Bloomington 1989. Arguably, though a kind of physicalism often associated with scientific realism is a pervasive element in twentieth-century naturalism and at least equally at present, anti-realism in metaphysics, unlike the thesis of the irreducibility of the normative, is compatible with naturalism.

[9] For a broader view that constitutes a philosophical naturalism, see the “liberal naturalism” set forth by M. De Caro in Naturalism in Question and in M. De Caro, A. Voltolini, Is Liberal Naturalism Possible, [in:] Naturalism and Normativity, eds. M. De Caro, D. Macarthur, Columbia University Press, New York 2010, pp. 69–86.

[10] Richard Swinburne argues in detail that the theistic view is simpler. For an indication of his view of simplicity, see The Existence of God, Oxford University Press, Oxford 2004, pp. 53–66, 70–71, and 179–179; and Epistemic Justification, Oxford University Press, Oxford 2001.

[11] For a brief discussion of how to interpret the razor principle and its possible role in evaluating design arguments, see R. Collins, The Design Argument: Between Science and Metaphysics, [in:] Analytic Philosophy Without Naturalism, eds. A. Corradini, S. Galvan, E.J. Lowe, Routledge, London 2006, pp. 140–152.

[12] For a concise but wide-ranging discussion of the internalist-externalist controversy, see my Epistemology: A Contemporary Introduction, London and New York, Routledge 2010, esp. chapters 10–11. These chapters also indicate why the notion of knowledge may be plausibly represented along reliabilist lines that do not require taking it to entail justification. If justification is not naturalizable, then, it does not follow that knowledge is not.

[13] Cf. Robert Koons on The Incompatibility of Materialism and Scientific Realism, in his Realism Regained, Oxford University Press, Oxford 2000, chapter 17, section 5.

[14] This possibility is described in some detail in ch 10 of my Rationality and Religious Commitment, Clarendon Press, Oxford 2012.

[15] For an excellent but too little studied paper on this issue see R. Cartwright, Propositions, [in:] Analytical Philosophy, ed. R.J. Butler, Blackwell, Oxford 1962, pp. 81–103. Among its points is the important one that sentences and propositions (or any bearer of truth value) differ in their arithmetic. The number of things said is determined differently than the number of sentences in which it may be said. If two people who, respectively, speak only English and Polish, say in their own languages that 7 + 5 = 12, there is one thing said and one truth, but there are two sentences.

[16] I appraise one version of Cornell Realism, and sketch some conceptions of moral explanation in Ethical Naturalism and the Explanatory Power of Moral Concepts, [in:] Naturalism: A Critical Appraisal, eds. S. Wagner, R. Warner, University of Notre Dame Press, Notre Dame 1993, pp. 95–115.

[17] As suggested in the text, if we had a complete list of the things that constitute a person’s obligation, we might say that to be obligated to A is equivalent to satisfying one or more of the descriptions. Depending on the character of the list, we might consider this a (disjunctive) analysis. But one might also insist on some unifying element, such as the notion of respect for persons, and go on to argue that here such an element must be normative. More is said below about the possibility of a disjunctive analysis.

[18] To be sure, there is a sense in which for any true proposition, there is a possible question to which it is a correct answer. My point here is that if the question is what properties a thing has or what properties of it explain something, it is at best atypical for a plausible answer to cite something that seems a genuinely disjunctive property. The issue is a large one, however, and what is said here is meant only to suggest problems that prima facie favor denying that predicative disjunctions of the kind in question express disjunctive properties.

[19] To be sure, anti-realists in ethics would say that since there are no moral properties, it is the predicates used to express them that should be said to be non-causal, but we need not dwell on this.

[20] In my Moral Judgments and Reasons for Action, in my Moral Knowledge and Ethical Character, Oxford University Press, Oxford 1997, which contains many references to relevant literature.

[21] See J.G. Hernandez (ed.), The New Intuitionism, Continuum, London 2011, for papers articulating and critically appraising this view.

[22] See ch 5 of my The Good in the Right: A Theory of Intuition and Intrinsic Value, Princeton University Press, Princeton 2004, for a description of the added grounding properties as well as refinements and corrections of Ross’s list of such properties.

[23] There is even a way for my view to be adapted to noncognitivism, as I noted in The Good in the Right, p. 151. But noncognitivism is not, to be sure, a natural option for an intuitionist.

[24] As Jaegwon Kim has put it, “One way of stating the principle of physical closure is this: If you pick out any event and trace out its causal ancestry or posterity, that will never take you outside the physical domain. That is, no causal chain will ever cross the boundary between the physical and the nonphysical.” See Mind in a Physical World, MIT Press, Cambridge, Mass. 1998, p. 41 (italics mine). For extensive critical discussion of this and other closure theses (particularly as represented in this and later work by Kim), see S. Goetz, C. Taliaferro, op.cit., esp. chapters 2 and 3.

[25] Elsewhere I have exposed a triple ambiguity, showing that none of the three readings depends on identifying mental properties with physical ones. See, e.g., The Theory of Explanation: Some Metaphysical, Scientific, and Intentionalistic Dimensions, forthcoming.

[26] Cf. David Papineau, who, though he takes naturalism to be committed to the completeness of physics, also maintains that although “a complete physics excludes psychology and that psychological antecedents are never needed to explain physical effects (...) psychological categories can be used to explain physical effects (...) in all such cases an alternative specification of a sufficient antecedent, which does not mention psychological categories, will also be available” (op.cit., p. 31, n.26).

[27] It is natural to say ‘tracing back to the creation’ but we must remember that one kind of divine creation is “from eternity,” in the sense that God creates the universe but not in time. This is perhaps arguably a kind of conserving causation; but, however it is to be conceived, I do not want to rule out the possibility. Note that determinism also implies an infinite past, on the assumption that there are events, that every event has an event cause, and that cause-effect relations take some minimal amount of time in the intuitive sense illustrated by paradigms of singular causal relations.

[28] Cf. Richard Swinburne’s view of overdetermination. He says (among other things) that when there is no connection between the joint determinants such that either one of them is dominant over the other(s) or they are common effects of the same cause, there is a coincidence. But he does not claim that there cannot be two distinct independent explanations. See The Existence of God, 2nd ed., Oxford University Press, Oxford 2004, p. 46. Overdetermination is indeed puzzling when the causal factors are taken to be independent; one naturally wants to say that the effect must be different. But consider instantaneous death in the case of a firing squad wherein all shots are deadly and simultaneous. The wound is different in some way given the multiple hits, but the death occurs at t as a result of each hit, and it is the significant event we take to be overdetermined.

[29] An earlier version of this paper was given at the Jagiellonian University of Krakow as part of a series I presented on Naturalism, Normativity, and the Explanation of Human Action, and I benefited much from discussing it there. The paper also reflects much that I have learned from discussions with colleagues, friends, and audiences, and it draws in several places on previous work, most notably Philosophical Naturalism at the Turn of the Century, “Journal of Philosophical Research” 2000, vol. 25, pp. 27–45; Can Normativity Be Naturalized?, [in:] Ethical Naturalism: Current Debates, eds. S. Nuccetelli, G. Shea, Cambridge University Press, Cambridge 2012, pp. 169–193; and Chapter 10 of Rationality and Religious Commitment, Clarendon Press, Oxford 2011. Thanks to Mario De Caro for helpful comments on the penultimate draft.