A Metaphysical Naturalist Manifesto

Keith Parsons, in his inaugural blog, declares that he is “new to this whole blogging thing, but [he] thought [he] would start off with a big post”—and thus provided us with his “Atheist Manifesto.” He expressed the desire “to hear what some of you think, and maybe get some others to submit their own manifestoes.” Well, what follows is my manifesto since I too am new to this whole blogging thing and thought I should also start off with a big post.

By metaphysical naturalist I mean someone who holds either that supernatural agents do not exist, or that their existence is antecedently improbable and that this antecedent improbability has not yet been satisfactorily overridden or discharged by available plausible evidences and arguments. What is a supernatural agent? It is any (physically) disembodied personal being such as God (as conceived in traditional theism), demi-gods, angels, and disembodied souls (i.e. spiritual substances which at one time animated human bodies). [The term disembodied person is qualified by a parenthesized “physically” so that the term supernatural person embraces persons who animate bodies (i.e., spatially extended substances) but are imperceptible (via ordinary sense perception) to humans or animals.] Although Keith Parsons refers to himself as being an atheist,[1] his published writings disclose that he is a metaphysical naturalist—as I use the term.

Now there are metaphysical naturalists and metaphysical naturalists; just as there are theologically conservative Christians and theologically conservative Christians. By all this I mean that there may be, and indeed are, some very sharp differences of belief or opinion among metaphysical naturalists just as there are among Christians. I do not regard someone as being a philosophical or ideological ally or a fellow team member, just because he is a fellow metaphysical naturalist. Of course, we can all profit from intellectual discourse, whether or not with naturalists or Christians of whatever school, or with other ists.

What kind of naturalist am I? I am (what I call) a commonsensible naturalist. So what is commonsensible naturalism? The term is inspired by Christian philosopher William Hasker’s article “What About a Sensible Naturalism? A Response to Victor Reppert”[2] By “sensible naturalism” Hasker means “a [metaphysical] naturalism that makes a really serious effort to accommodate, or at least to make sense of, our ordinary convictions about the mind and its operations-the things we all think we ‘know’ about the mind, when we are not doing philosophy.”[3] The notion can usefully be extended to those fundamental deliverances of natural reason which constitute first principles pertaining to such matters as our knowledge of the external world, other minds, memory, and causation. I prefer to use the term commonsensible instead of sensible naturalism because it is a metaphysical naturalist version of a foundationalist philosophy based upon common sense.

Metaphysical naturalists who reject a commonsense foundationalist philosophy (or any other first philosophy) may not like to be called non-sensible naturalists. But they are likely not to mind being called non-commonsensible naturalists; and perhaps some even might take pride in being so called since rejection of the so-called deliverances of a commonsense first philosophy is considered chic in some quarters.

I now should like to set forth some important components of commonsensible naturalism.[4]

First: an emphatic rejection of the principle of causal closure in the physical domain and its twin-sibling– epiphenomenalism, with an equally emphatic affirmation of mind-body interaction. In short, some physical and mental events or state are severally caused by some other mental events or states, whether qualia or intentional (i.e., having the quality of aboutness, e.g. volitions or purposings, beliefs, desires). To be sure, there are physical events, states, or processes necessary for mental events or states to be causally efficacious.

Second: an affirmation that human practical and theoretical reasoning encompasses more than just computational thinking–that mechanistic “manipulation” of information by logistical rules, whether or not accompanied by consciousness. But reasoning involves conscious apprehension of the logical relations among propositions, classes, and the like—so that we intuit, for example, that proposition r must be true because propositions p and q are true, and that their logical relation entails the truth of proposition r. We know, in some cases, that we believe proposition r to be true because we have apprehended the true logical relation subsisting between propositions p, q, and r, and that these propositions are true. Similar considerations apply, necessary changes being made, to inductive reasoning. Humans are unique among all sentient animals in having the power of propositional speech and reasoning.

Third: given mind-body interaction, the commonsensible naturalist might conceivably be an emergent substance-dualist—someone who holds that the mind is an emergent, immaterial entity produced by the human body (specifically the brain) when it becomes sufficiently configured in an appropriate way and which will cease to exist when the brain ceases to so configured. Another possible scenario, which I prefer, is that the human mind is the human brain which when appropriately configured has various mental powers or capacities (or the capacity to have such capacities), such as that of reasoning, imagining, perceiving, remembering, willing, and so forth. And there are other possible scenarios consistent with the overall view of the commonsensible naturalist that mind-body interaction obtains and that minds necessarily be embodied.

Fourth: commonsensible naturalism includes an acceptance of a first philosophy: namely metaphysically necessary synthetic principles or postulates (none self-evident in the usual strict senses or a falsifiable empirical generalization), which are presupposed and implicit in the making of our properly basic and incorrigible commonsense beliefs (such as the existence of the external world or of other minds), and in the making of generalizations and inferences in ordinary life, as well as in historical, scientific, and forensic inquiry. These first principles are what some call the fundamental deliverances of natural reason. [Among these principles is the causal principle that whatever begins to exist must have a temporally prior cause for its beginning. (I do not concern myself here quite different issues pertaining to epistemic or ontic determinism.) For the commonsensible naturalist, the cause for the beginning of any natural substantive entity in our universe is itself natural—and this applies as well to the universe as a whole if it is the case that it began to exist. That temporal series which includes (or is constituted by) the history of this universe is of infinite duration and consists of denumerably infinite natural events.[5]]

Fifth: commonsensible naturalism, as I use the term, involves acceptance of some version of the dynamic or tensed A-theory of time, according to which events are temporarily ordered by tensed determinations as past, present, and future, and so temporal becoming is ontologically objective (i.e., mind independent)—thereby rejecting the B-theory of time according to which events are only ordered by the tensiveless relations of earlier than, simultaneous with, and later then, such that temporal becoming is ontologically subjective (i.e., mind dependent).

Last, but not least, commonsensible naturalism is committed to some version of an (at least epistemologically) objective moral order (i.e., a natural morality), understood to embrace what are commonly understood among men and women of good will to be basic moral principles, precepts and norms universally binding on humanity for reasons other than being required by customary mores, or human or divine positive law, or as having been supernaturally revealed.

Keith Parsons invited comments with respect to his manifesto. Here are a few. At the outset, I should like express my appreciation for his scholarly articles, which I have often found very instructive and with which I agree on many issues.[6] Nevertheless, he is not a commonsensible naturalist. Quite evidently, he does not accept the principle that every natural event must have another event as a temporarily prior causal ancestor. Regretfully, he claims that “most people reply with amateur versions of the first cause or design arguments.” A reader might naturally infer or suspect (and, if so erroneously) that intelligent theists (William Lane Craig, for example) do not agree that to say that nothing existed before the big bang simply means “There wasn’t anything prior to the big bang.” Some readers might also erroneously think that intelligent theists (again Craig, for example) typically maintain the patently ridiculous position the first cause argument involves the principle that everything had to have a cause—rather than there must be a cause (but not necessarily a determinative one) for every beginning of the existence of a substantive entity. [Where Craig is definitely wrong, in my opinion, is that he holds upon philosophical grounds that any infinite temporal series (whether or not of infinite duration) is metaphysically impossible, and asserts that the Big Bang standard model confirms his thesis.]

Parsons appears to think it at least factually possible (based upon physical cosmology) that this universe had an absolute temporal beginning. However, the post by bpabbott is right on point when he declares: “due to the physical limitations of space and time, we are effectively censored from events prior to the big bang. Although, the events, following the big bang, exhibit no discernible effects respecting pre-big-bang causes, it is erroneous to infer/imply/assume there were no “pre-big-bang” causes.”

Parsons claims that our “common-sense intuitions simply might not apply to the realities studied by fundamental physics.” True enough; but some alleged realities of fundamental physics are (or may be) just theoretical constructs of a high-level scientific model highly instrumental in organizing and predicting observations. So it is just begging the question to assert that some theoretical constructs of fundamental physics denote realities. And then it is (or may be) the case that many commonsense intuitions are not indefeasible because they are not actually constitutive of a first philosophy. [Parsons evidently thinks that the proposition that one and the same electron can simultaneously be in two places is true. I believe it to be false—even though it is derived from a scientific model which is very useful in organizing and predicting observations.]

And here is Guminski’s complaint: It is unfortunate that metaphysical naturalism is so frequently expounded (whether explicitly or not) as necessarily incompatible with fundamental and indefeasible common-sense principles which reasonable men and women are not going to reject just because such principles are supposed to be inconsistent with the deliverances of some natural scientists and some philosophers of natural science. And here is Guminski’s major thesis: commonsensible naturalism has all the resources necessary to defeat the plausible claims and arguments of supernaturalists, including those of any positive religion such as Christianity.

[1] There are some atheists (whether they simply assert that they do not believe that God exists or instead positively deny his existence) who are not metaphysical naturalists because they believe that there are disembodied spirits—such as human souls while in a disembodied state.
[2] Philosophia Christi 5 (2003) 53-62.
[3] Ibid., 53.
[4] See my “The Moral Argument for God’s Existence, the Natural Moral Law, and Conservative Metaphysical Naturalism” (2004) http://www.theologyforum.net/ for a description of what in this article I call commensensible naturalism. Upon reflection, I have abandoned the word “conservative” as having been improvidently chosen.
[5] See my three articles on the Kalam Cosmological Argument (available on the Secular Web www.infidels.org/library/modern/arnold_guminski/index.shtml) in which I argue for the metaphysical possibility of an infinite temporal series of infinite duration consisting of denumerably infinite events.
[6] Unfortunately, Parsons mars his manifesto by referring to James Dobson as a “neanderthal…type.” Is this kind of public bashing of Dobson a good thing?

About Arnold Guminski

I received my BA (history and philosophy) from the University of Buffalo (1952), and my JD from the University of California at Los Angeles School of Law (1956). I was admitted to the California State Bar in 1957. After six years of active duty with the US Army, I was a deputy district attorney for Los Angeles County for twenty-nine years. For twenty years I was assigned to the appellate division, and argued two cases before the United States Supreme Court.

Since my retirement in January 1993, I have resided in Boulder, Colorado with my wife, Annegret. I am an independent scholar, and several articles by me have appeared in peer-review print and on-line journals. My book, THE CONSTITUTIONAL RIGHTS, PRIVILEGES, AND IMMUNITIES OF THE AMERICAN PEOPLE [subtitle omitted] was published in 2009.


My wife and I very much like to travel at home and abroad. We love dancing: contra, folk, polka, ballroom, etc.

  • http://www.blogger.com/profile/09565179884099473943 Hallq

    I agree with a lot of what you say… but why bother keeping the naturalism/supernaturalism distinction, as anything but shorthand? I can’t see what use it is metaphysically.

  • http://www.blogger.com/profile/08414754510736349472 Tom Clark


    By “sensible naturalism” Hasker means “a [metaphysical] naturalism that makes a really serious effort to accommodate, or at least to make sense of, our ordinary convictions about the mind and its operations-the things we all think we ‘know’ about the mind, when we are not doing philosophy.”

    Isn’t this what philosophy is supposed to do, namely “make a really serious effort to accommodate, or at least to make sense of, our ordinary convictions about the mind and its operations-the things we all think we ‘know’ about the mind”? Ordinary convictions are our intuitions, which serve as starting points in inquiry, but which are sometimes revised in gaining a conceptually cleaner handle on things. Sometimes we make sense of our convictions (that is, incorporate them into a theory) by seeing that they are artifacts or illusions. Same thing, perhaps, for some of the “fundamental deliverances of natural reason.” Questioning commonsense isn’t chic, nor do I take pride in it, it’s just what philosophers and scientists commonly do. So I’m not sure I buy your commonsensualism even though I’d describe myself as a sensible naturalist.


    Tom Clark

  • http://www.blogger.com/profile/08414754510736349472 Tom Clark

    Actually, maybe I would buy commonsensualism, but not commonsensibilism.

  • http://www.blogger.com/profile/16826768452963498005 Jim Lippard

    “Unfortunately, Parsons mars his manifesto by referring to James Dobson as a “neanderthal…type.” Is this kind of public bashing of Dobson a good thing?”

    By ad hominem alone, probably not. But given the facts about Dobson in Gil Alexander-Mogerle’s book _James Dobson’s War on America_ (1997, Prometheus) and Dobson’s subsequent support of the Bush administration, I think criticism of Dobson is not only a good thing but essential.

  • http://www.blogger.com/profile/16718427136116646031 kaugust

    Hi Arnold,

    If possible, could you provide me some clarification as to why you think interactionist substance dualism (a la Hasker) is a tenable position as opposed to your own interactionist *property* dualism?

    For instance, you write: “the commonsensible naturalist might conceivably be an emergent substance-dualist–someone who holds that the mind is an emergent, immaterial entity produced by the human body (specifically the brain) when it becomes sufficiently configured in an appropriate way and which will cease to exist when the brain ceases to so configured.”

    This implies that the mind is existentially dependent upon the brain. But is mind-brain dependence really compatible with *substance* dualism? My understanding of the concept of a substance is that it is, by definition, existentially independent of other substances. So if the mind is one kind of substance (spirit), the brain another kind of substance (matter), mind-brain dependence seems to me incompatible with substance dualism. William Hasker thinks that by inserting “and then a miracle occurs” at the moment of death, the emergent substance which would otherwise die can be miraculously preserved by God–but ironically he could have held this view as a reductionist materialist (perhaps God copies the information in your brain and restores it elsewhere, as ‘soulless’ resurrectionists believe).

    If mind were a separate substance from the brain, then in principle it could survive without the brain. It might not as a matter of fact; but like the brain that needs a heart to survive, that heart could be replaced with something else providing blood to the brain (like a bypass machine). It seems to me that you cannot rule out the possibility of survival after death if substance dualism is a live option for you; only property dualism can do that, because properties cannot survive once the substance they inhere in is destroyed.

    Am I misunderstanding your position?

  • http://www.blogger.com/profile/18096250594171764297 Arnold Guminski

    Hi Keith!

    Thanks for your recent post in which you question my assertion (in “A Metaphsical Naturalist Manifesto”) that it is consistent with commonsensible naturalism for someone to hold to a version of substance dualism in which (to use my words) “the mind is an emergent, immaterial entity produced by the human body (especially the brain) when it becomes sufficiently configured in an appropriate way and which will cease to exist when the brain ceases to be so configured.” You comment: “This implies that mind is existentially dependant upon the brain.” But you then ask: “But is mind-brain dependence really compatible with ‘substance’ dualism?” You explain that you understand the concept of a substance to be “that it is, by definition, existentially independent of other substances.”

    Your argument is that the mind and brain, according to emergent dualism, are different kinds of substances, and so mind-brain dependence seems to him incompatible with substance dualism. So, unlike properties of a thing which cannot survive once the substance they inhere in is destroyed, “if mind were a separate substance from the brain, then in principle it could survive without the brain.” But you acknowledge: “It might not as a matter of fact …” It seems to you that I “cannot rule out the possibility of survival after death if substance dualism is a live option for [me].”

    You’re aware that I am not an emergent, interactionist substance dualist, but rather an interactionist property dualist. So all that I am saying is that emergent dualism is consistent with commonsensible naturalism. This is very much like a theologically orthodox Catholic and a theologically orthodox Calvinist agreeing they are both Christian, albeit the former but not the latter believes that the Pope is doctrinally infallible if certain conditions are satisfied.

    The term substance is indeed ambiguous. So I accept that, according to one definition of the term, the notion of substance precludes the relation of existential dependence of one real entity upon another—although, according to virtually all theologically conservative monotheists, all concrete entities now existing are existentially dependent upon the conserving volition of God. But there are other definitions in which the term substance, particularly with respect to living organisms, is used to denote one organism which is a structurally and functionally distinct from other organisms. If one speaks of an adult human and his right arm we are not talking about two substances but one only. But if we speak of a pregnant woman bearing a pre-viable fetus, then we are speaking of two substances and not one. But the pre-viable, post-embryonic fetus is surely existentially dependent upon its mother even though some extraordinary medical procedures might keep it alive for a short time after the mother’s death. So I do not see that it follows that just because (per hypothesis) the human body, when sufficiently configured, generates an emergent, immaterial mind that there cannot be the relation of existential dependence between the sufficiently configured human brain and the emergent, immaterial mind. By the way, according to a naturalist version of emergent substance dualism, the emergent mind could cease to exist when the brain no longer exists (i.e., brain death) or when it ceases to be sufficiently configured. I’ll grant you, however, that were I to use the term “separate concrete entity,” instead of using “substance,” I might spare myself the need to further explain my position.

    You say that “in principle [the emergent immaterial mind] could survive without the brain [although] it might not as a matter of fact.” What do you mean by “in principle”? For all we are concerned about are matters of fact, whether real or supposed natural facts (i.e., pertaining to this physical universe) or real or supposed metaphysical facts (pertaining to any past, present, or future universe). Moreover, according to you, I “cannot rule out the possibility of survival after death.” So, in the first place we must distinguish between logical possibility, and metaphysical and natural possibilities. Yes, it is logically possible that the emergent immaterial mind to survive the death of his erstwhile corporeal companion: i.e., there is no logical contradiction involved. But if there is neither any supernatural being nor one with the requisite power to create immaterial minds or keep them going post-mortem, then I believe that the post-mortem survival of an emergent, immaterial mind in this, our universe, would be naturally impossible assuming (for argument’s sake) that such minds existed. Furthermore, I think that it is very antecedently improbable that there is, ever was, and ever will be, any other physical universe (i.e., a universe which contains physical entities not spatially related to any physical entity in this universe) in which such survival is naturally possible in each such universe. The hypothesis of emergent substance dualism, in my opinion, is far less probable than that of interactionist property dualism. And so for me, emergent substance dualism at best is a barely alive option.

    So, yes, an emergent substance dualist (e.g., someone like William Hasker who denies the factual possibility of post-mortem survival of the mind) could be a naturalist in my lexicon. But that someone is a metaphysical naturalist does not mean that his or her version of naturalist is even. I hold that some versions of naturalism are more-or-less antecedently improbable; for example, a naturalism that asserts that the history of this universe involves an infinite temporal series of events or moments of finite duration). But, quite frankly, I consider a naturalism that asserts emergent substance dualism is less improbable than one that asserts the factual possibility an infinite temporal series of finite duration. Of course, that one version of naturalism (in my opinion) is less improbable than another does not mean that any particular adherent of either version is unreasonable, or that his arguments do not deserve serious and respectful consideration on their merits.