Much work on “science and religion” or “science and spirituality” seeks to integrate harmoniously the findings of contemporary science with an ancient spiritual tradition like Christianity or Buddhism (Barbour 1997, 2000; Clayton 2004, 2008; Dalai Lama 2005; Haught 2000, 2003; Wallace 2003, 2007, 2009). In this paper, I offer a different vantage point, as I see the contemporary sciences of the mind‐brain as giving us ample reason to be skeptical of many of the claims found in religious spiritualities. A great deal of religious spirituality presumes a commitment to fairly robust versions of metaphysical dualism. On the other hand, disciplines like neuroscience, cognitive science, and analytic philosophy of mind not only give us every reason to think that the mind is the brain, they have also begun to offer compelling bio‐psychological explanations for the ubiquity of concepts of God and soul across cultures. What sorts of consequences does materialism ¹ have for spirituality? In this paper, I explore that question in four sections.

I first establish the link between spirituality and dualism and argue that contemporary scientific and philosophical work being done at the mind‐brain interface gives us reason to be skeptical of dualism. I then examine the consequences of materialism, if true. Materialism or naturalism is widely understood as an anti‐religious stance with corrosive effects on morality. I argue that naturalism, in fact, provides a compelling empirical approach to morality with objective traction. While naturalism registers some significant intellectual differences with religious spiritualities, I further argue that nothing precludes naturalism from engagement with the great spiritual traditions of the world, and nothing precludes respectful dialogue between naturalists and religious believers.

Spirituality and Dualism

Like religion, spirituality is notoriously hard to define, but it is relatively uncontroversial to note that spirituality typically involves beliefs concerning God, gods, spirits, souls, or consciousness capable of existing without any material or physical substrate. Many forms of spirituality involve strongly dualist views. Christianity and Buddhism, the spiritual traditions that have the most engagement with contemporary science, provide clear examples.

Perhaps the most obvious example of religious dualism comes from within classical Christian theism. Within classical Christian theism, God is understood straightforwardly as an immaterial person. Richard Swinburne captures this understanding well when he defines God as “[a] person without a body (i.e., a spirit) present everywhere, the creator and sustainer of the universe” (Swinburne 1977, 2). The notion of God as an immaterial person relates intimately to the notion of human beings possessing an immaterial soul along the lines described in the Catechism of the Catholic Church: “The Church teaches that every spiritual soul is created immediately by God… and that it is immortal: it does not perish when it separates from the body at death, and it will be united with the body in the final resurrection” (Catholic Church 1994, #366).

Notions of immaterial mind and consciousness also figure prominently in a tradition like Buddhism that lacks both the notion of God and a substantial soul. Such views can be seen in the recent writings of the fourteenth Dalai Lama and one of his English translators, B. Alan Wallace (Dalai Lama 2005; Wallace 2003, 2007, 2009). In an article called “On the Luminosity of Being” the Dalai Lama writes: “There is no reason to believe that the innate mind, the very essential luminous nature of awareness, has neural correlates, because it is not physical, not contingent upon the brain. So while I agree with neuroscience that gross mental events correlate with brain activity, I also feel that on a more subtle level of consciousness, brain and mind are two separate entities” (Dalai Lama and Goleman 2003, 42).

Of course, a significant number of Christian philosophers and theologians engaged with mind science reject the notion of the soul. But it is important to note that at least one case of an immaterial mind remains within these revisionist forms of theism. Theistic emergentism is still a fundamentally dualist position. Philip Clayton, arguably the thinker who has offered the most sophisticated treatment of emergentism from a theological perspective, frankly acknowledges this in his monograph Mind and Emergence:

While this position [theistic emergentism] affirms that all mental phenomena in the empirical world are dependent on a biological substrate, it postulates that transcendent mind is not downwardly dependent in this way. This fact accounts for the ineliminable element of dualism in the theistic hypothesis…[T]his move forces the chain of explanation beyond the framework that one otherwise uses to explain mental properties, in so far as it imagines a mind that is distinct in essence from the natural order taken as a whole. (Clayton 2004, 183–84)

Dualism in Question

When one reads contemporary scientific and philosophical literature on the conscious self, one cannot but be struck by its distance from the metaphysical and methodological commitments of even the most scientifically informed religious dualists. Bio‐psychological explanations of the conscious self are being actively pursued, and most of these research programs are guided by the assumption that mind can be identified with the brain.

What sorts of factors motivate an identity theory of mind? Identity theory becomes compelling when one realizes the constraints that modern science places on our theorizing about mind. The first constraint, highly significant for the issue of mental causation, one might call the physics constraint. It seems an obvious empirical fact about the world that the conscious self has physical effects in the world (e.g., I go to the refrigerator to get a drink because I am thirsty). Now, physics places important constraints upon our thinking about such activities. Physics operates under conservation laws and the notion that every physical effect has a physical cause (the causal closure of the physical). If the mind is nonphysical, one runs into massive difficulties in trying to account for mental causation. ² As Owen Flanagan notes: “for physical energy to increase in any system, it has to have been transferred from some other physical system…If we accept the principle of the conservation of energy we seem committed either to denying that the nonphysical mind exists, or to denying that it could cause anything to happen, or to making some very implausible ad hoc adjustments to our physics” (Flanagan 1984, 21).

Next, consider the biology constraint. Evolution is a process operating on physical systems; that the human mind is also a physical system makes perfect sense in an evolutionary framework. As Paul Churchland writes: “Like all but the simplest of organisms, we have a nervous system. And for the same reason: a nervous system permits the discriminative guidance of behavior. But a nervous system is just an active matrix of cells, and a cell is just an active matrix of molecules. We are notable only in that our nervous system is more complex and powerful than those of our fellow creatures” (Churchland 1984, 21).

Finally, consider the mind‐brain correlations and dependencies described by the contemporary neurosciences. As Patricia Churchland notes:

The degeneration of cognitive function in various dementias such as Alzheimer's disease is closely tied to the degeneration of neurons. The loss of specific functions such as the capacity to feel fear or see visual motion are closely tied to defects in highly specific brain structures in both animals and humans… One of the most metaphysically profound discoveries in this century showed that a human's mental life is disconnected if the two hemispheres of his brain are disconnected… In careful postoperative studies of the capacities of “the split‐brain” subjects, Roger Sperry, Joseph Bogen, and their colleagues found that each hemisphere could have perceptual experiences or make movement decisions independently of the other… These remarkable results demonstrate that the unity of mental life is dependent on the anatomical connections in the brain itself. This seems reasonable enough on the hypothesis that mental life is activity in the brain. (Churchland 2002, 43–44)

Identity theory becomes compelling not simply on the basis of such constraints, but also given the fact that it functions as a kind of regulative ideal in the neurosciences (Flanagan 2002). Identities are not simply conclusions but heuristics guiding future research (McCauley and Bechtel 2001). Ilya Farber describes this ambition well:

The goal of the NCC [Neural Correlates of Consciousness] project is not to produce a causal model on which consciousness stands apart as a product of the brain, but rather to find the patterns of consciousness within the structure and dynamics of the brain. The methodology for pursuing this goal has already been charted out by researchers studying memory and perception: in roughest outline, it involves functionally decomposing the cognitive process in question, functionally and physically decomposing the brain, and trying to find matching patterns amidst the bits on each side. This process is fundamentally analogical rather than correlational, and the relation that it attempts to establish is not one of causal interaction but one of identity. (Farber 2005, 81)

The contemporary sciences of the mind give us every reason to think the mind is the brain. ³ But what about the ubiquity of dualist notions like God and the soul across cultures? Interestingly the burgeoning discipline of cognitive science of religion is beginning to offer bio‐psychological explanations for such concepts (Atran 2002; Bering 2006; Bloom 2004; Boyer 2001; Tremlin 2006). According to the cognitive science of religion, we are “natural‐born dualists” (Bloom 2004) and supernaturalists. We are creatures of matter led to think that we are not. If such a view is correct, it puts contemporary mind science and traditional spirituality on a collision course. There are certainly many ways of trying to keep God and/or the soul in the picture; however, these attempts at integrating religious beliefs with science have not captured broad assent within the contemporary scientific and philosophical community. Concepts like “God” and “soul” have the feel of optional accessories: there if you need them, but capable of being shaved away with one stroke of Occam's razor if you do not. I think it is better to bite the materialist bullet and see where we can go from there.

Materialist Spirituality: Materialism and Morality

I have been concerned with establishing the plausibility of materialism based on its coherence with the findings and methods of contemporary science. However, there is a widespread worry that materialism or naturalism, if true, is a fundamentally unlivable position, one with devastating consequences for morality and meaning. Many of the worries about the consequences of materialism center around issues of moral objectivity. The dualism embedded in religious spiritualities like Christianity and Buddhism is linked closely to a certain eschatological vision, whether it be karmic rebirth, immortality of the soul, or resurrection of the body, and this dualist‐eschatological vision is connected to a certain notion of moral objectivity. Consciousness or the self is linked to a broader cosmic meaning or purpose beyond the mundane world.

It is widely assumed that this dualist‐eschatological vision is necessary to secure objective morality. But is the appeal to religiously sanctioned morality really all that compelling? Appeal to religious morality seems to suggest that there is consensus on what the content of that morality is, when, in fact, there is no such consensus. Thus, the specter of relativism is equally an issue for religious morality as it is for naturalistic morality. In fact, appeal to the transcendent seems to make moral disagreement even more intractable, as claims about the transcendent have proved difficult, if not impossible, to adjudicate. Transcendent morality grounded in a dualist‐eschatological vision is at least as morally problematic as naturalistic morality.

Concerns about moral objectivity are real and important, but appealing to religion is the wrong way to secure it. I want to suggest that there is a more empirical notion of moral objectivity available. It is very important to move beyond thinking that our moral alternatives are either objective transcendent morality or subjective relativism. I have already noted the problem with a dualist‐eschatological understanding of moral objectivity. Subjective relativism is false on both a descriptive and normative level. On a descriptive level, there is mounting evidence that the human moral sense is rooted in our biology and our evolutionary past, and, for that reason, is not merely a product of individual subjective whim or social construction. If this is true descriptively, it has important implications for how we think about morality and ethics normatively.

In recent work, Owen Flanagan has outlined one helpful approach to naturalistic ethics (Flanagan 1996, 2002, 2007). Far from undermining ethics, Flanagan helps show how armed with the wisdom we have gained from the mind sciences, ethics can be pursued as a kind of “human ecology” (Flanagan 1996, 2002). “Ecology is the science that studies how living systems relate to each other and their environment, so it is the relevant analogy… For any natural system, we can ask what sorts of conditions enable the system and its components to flourish… Ethics, as I conceive it, is the systematic inquiry into the conditions that permit human beings to flourish” (Flanagan 2002, 266–67). Thus, the ancient quest for flourishing or eudaimonia can be pursued with greater empirical traction. “Eudaimonics, as I conceive it… , provides a framework for thinking in a unified way about philosophical psychology, moral and political philosophy, neuroethics, neuroeconomics, and positive psychology, as well as about transformative mindfulness practices… Eudaimonics is the activity of systematically gathering what is known about … these components of well‐being and attempting to engender as much flourishing as possible” (Flanagan 2007, 4).

As Flanagan notes, if we conceive of ethics in such a manner, we can secure ethical objectivity by engaging in meta‐ecology, isolating “the conditions of human flourishing that are not just our own, but that apply across human habitats” (Flanagan 2002, 289). Flanagan cites the “capabilities approach” of Amartya Sen and Martha Nussbaum, as an example of such a meta‐ecological approach (Nussbaum 2000). “According to this approach, we ask what an average human is capable of achieving if she is given the chance to develop. The key question is not whether she accepts or approves of her way of being or living, but whether she has chances to develop her human capacities” (Flanagan 2002, 289). It is thus possible to develop criteria of flourishing that allow for moral objectivity while attending to cross‐cultural difference.

Materialist Spirituality: Materialism and Religion

Naturalism is skeptical about the dualist assertions advanced in many religious traditions. It is important to emphasize that this is a point of intellectual disagreement; the naturalist regards the dualist claims of religious spiritualities to be false. This does not preclude a robust appreciation for many other aspects of religion. Nor does it preclude conversation and dialogue between naturalists and religious believers. Among other things, religious wisdom traditions have developed techniques for probing, exploring, and transforming consciousness. These techniques originally developed in a dualist setting but such techniques are fundamentally compatible with naturalism. There is no reason why a naturalist should not be interested in these attempts at human transformation and no reason why naturalists and adherents of religious spiritualities cannot engage in collaboration and dialogue on these questions. ⁴

Intellectual disagreement need not preclude conversation and dialogue. Indeed, it seems that one important measure of a spirituality—whether religious or naturalistic—is its ability to engage visions that are fundamentally different from its own. For all the interest in interreligious dialogue, there is surprisingly little said about dialogue between naturalists and religious believers. Naturalism is widely regarded as an anti‐religious stance, but this need not be the case. One can find naturalistic literature that labels religious believers as deluded and morally dangerous. One can also find materialists labeled as “literalists” and “fundamentalists” in theological literature attempting to integrate religion and science. If we want a genuine dialogue between religion and science, we have to promote intellectual disagreement while avoiding all‐too‐easy anti‐naturalist or anti‐religious sentiments. Anti‐religious naturalism and anti‐naturalistic religion are non‐starters for dialogue, but muting disagreement between naturalism and religious dualism is problematic as well. Both naturalistic and religious spirituality need to encourage dialogue where differences can be raised with integrity and even in friendship.

A model for what I have in mind is suggested by the great naturalist philosopher, David Hume, in his Dialogues on Natural Religion (Hume [1776] 1992). It is significant that Hume uses the genre of dialogue to probe central issues concerning religion. It is particularly significant to note that the deep philosophical and religious differences between Philo and Cleanthes occur in the context of mutual respect and deep and abiding friendship. In his commentary on the Dialogues, William Lad Sessions remarks:

[T]hey deeply trust and respect and like each other. They do not merely understand each other's subterfuges and strategies; they have no fear of divulging their deepest hopes and views to one another, even though they do not see things from a single point of view… Theirs is not an arrangement of convenience or domination; it is, to borrow George Fox's great phrase, a society of friends. This society, I believe … is intended to model for Pamphilus an enticing form of life, one that can explore the great issues of religion without erupting into superstition or enthusiasm—a form of life that can enfold deep difference and honest debate within its respect for persons. (Sessions 2002, 230)

Such a form of life is surely an essential ingredient in both materialist and religious spiritualities.

In this paper, I have argued that religious spiritualities stand in tension with scientific and philosophical work being done at the mind‐brain interface, and I have also defended materialism against the charge that it is an anti‐religious stance with corrosive effects on morality. The reflections of this paper are not offered merely as a critique of dualism and a defense of materialism. They are also offered to invite and encourage broader dialogue on issues concerning religion, science, and spirituality.