(June 30, 2024)
1. Introduction
Descartes famously argued for substance dualism from the mere conceivability of disembodied existence. Are modal arguments from the possibility of disembodied existence for substance dualism such as this successful or necessarily circular? Swinburne[1] has offered several reformulations of the Cartesian argument which seek to repair it. However, these "repaired" versions of the argument are accused of being question begging by Everitt,[2] and epistemically circular by Hasker.[3] Swinburne[4] has responded to these objections, and his responses rely upon what Tidman[5] calls the “conceivability thesis,” namely, that if some state of affairs S is conceivable, that it is possible. Kim raised several concerns about the use of the conceivability thesis to judge metaphysical possibility in modal arguments of this kind.[6] Although it may be tempting to believe that the modal argument from the possibility disembodied existence is not epistemically circular because one might accept the possibility premise without ever understanding the conclusion. In this paper I will argue that this kind of modal argument is necessarily circular for nobody who is not already a dualist can accept the possibility premise.
2. Restatement
Swinburne offered a detailed revision of the modal argument from the possibility of disembodied existence for the soul.[7] The argument may be summarized this way:
The structure of the argument is valid, however the problem is with premise 2, which is not a premise that a non-dualist could accept. Hasker says “the premises cannot reasonably be accepted by anyone not already convinced that the conclusion is true.”[8] Nobody sufficiently informed about the claims could could affirm p ∧ q ∧ s as metaphysically possible if they do not think already that there is a non-bodily part to human beings which can exist consciously independent of the body. Swinburne counters these kinds of objections by saying that someone might accept the possibility premise without ever understanding the conclusion of the argument or even knowing what a soul is. Swinburne writes that “it does not seem plausible to suppose that the argument is epistemically circular in the stated sense—since someone might accept the premises without ever understanding the conclusion.”[9] Further, Swinburne also responds that the truth of premise 2 depends upon “the coherence of various thought experiments described in two pages of my text; including ones easily graspable by seven-year old religious believers or readers of fairy stories.”[10] The thought experiments describe the continued existence of Swinburne after various things happen to his body. But regarding dualistic arguments of this kind Kim raised the following questions.
"Is it possible that I exist without a body? That surely is conceivable Descartes would insist. But again, is something possible just because it is conceivable? Can we say more about the possibility of our disembodied existence?"[11]
To consider some state of affairs S as conceivable, genuinely conceivable, one must know the nature of the entities in question. Even if it seems easy to imagine a ghost, an angel, or some other disembodied mind as existing and conversing with us about the weather it still may be impossible. Someone might visualize an encounter with such a being—however, it might still be metaphysically impossible if the full nature of the thing is not comprehended. It might seem possible that a ghostly voice emanates from the soul of a departed loved one asking about the clouds and rain, but once it is comprehended that souls are supposed to be unlocated and non-physical, it makes little sense to suppose that they could speak audibly without any speech organs. Many similar concerns may shroud Swinburne’s thought experiments, but I do not have room to discuss them directly.
3. Extracted Argument
1. To accept the possibility premise, one must already be a dualist.
2. If one must already be a dualist to accept the possibility premise, then modal arguments for the soul from the possibility of disembodied existence are epistemically circular.
C. Hence, modal arguments for the soul from the possibility of disembodied existence are epistemically circular.
4. Summarize Defense of Premises
The first premise of my argument claims that one must be a dualist of some kind to accept the possibility premise of modal arguments of this kind. Swinburne says “someone might accept the premises without ever understanding the conclusion.”[12] This does not seem to be entirely correct. Take the proposition:
‘It is possible that I will continue to exist consciously after my body (and anything that might potentially be considered my body) is suddenly destroyed.’[13]
By sudden destruction I mean the total destruction of the body, say in a nuclear explosion rather than by gradual replacement of parts over time, “that is, in the middle of a period while I am now thinking my body is suddenly destroyed.”[14] But that proposition could only be true if the following proposition were already accepted as true.
‘I now have a non-bodily part.’
If I do not have a non-bodily part then I could not continue to exist after my body is destroyed. It is possible that a physicalist could affirm that I might continue to exist after my bodily parts are destroyed because composition is not identity. I consider this body to be me (or at least part of me,) even though my cells have all been gradually replaced many times over, and this does not require having any non-bodily parts. But Swinburne is referring to the utter destruction of the body, which is to say, the sudden destruction of my present body and any other physical thing that might be considered my body and my continued conscious existence thereafter. It does not seem that any physicalist could ever accept the possibility of such a scenario because it would require having a non-bodily part which persists after any body that I might have is destroyed. Conscious existence after sudden destruction of the body should only be regarded as conceivable, if it is already accepted that disembodied conscious existence is metaphysically possible. Hence, I do not think it is true that someone might affirm the premises without ever understanding the conclusion. For a sufficiently informed reader to accept premise 2, they must believe they have a non-bodily part which is capable of conscious existence in 1985 even after the sudden destruction of their body in 1984 is to implicitly affirm r before the conclusion is ever arrived at by the argument.
The second premise states that the modal argument from disembodied existence is circular because one must be a dualist to accept the possibility premise. Every modal argument for the soul of this kind must have a possibility premise of this sort, stating something like ‘it is possible for me to exist consciously without a body’ or ‘it is possible that I exist after any body I could have is suddenly destroyed.’ Therefore, the same kind of circularity issue found in Swinburne’s argument reappears in all such arguments. Any claims about the possibility of existing without a body will inevitably involve assessing the coherence of our minds existing without our bodies. To assess whether it is conceivable that some human mind M can exist after the destruction of the body it is associated with B, one must already know the nature of M and B to truly conceive of whether M can exist without B. The identity theorists would say it is not metaphysically possible for M to exist without his B, because the mind is identical with the brain. However, a naturalistic dualist might accept the logical possibility of the claim but deny that it is metaphysically possible, treating physicalism as a contingent truth.[15] Kim also raised the question of whether conceivability, of itself, is a sufficient guide for judging possibility, concisely he says, “Conceivability may not in itself imply real possibility, and the exact relationship between conceivability and possibility is a difficult and contentious issue.”[16] I believe that conceivability is a valuable criterion for judging possibility, but it may not be sufficient on its own in every case. There are some states of affairs that are conceivable, and can be visualized but which turn out to be either impossible or necessarily true, Kim explained.
“We seem to be able to conceive how Goldbach’s conjecture, the proposition that every even number greater than two is the sum of two prime numbers, might turn out to be true, and also to conceive how it might turn out to be false. But Goldbach’s conjecture, being a mathematical proposition, is necessarily true if true, and necessarily false if false. So it cannot be both possibly true and possibly false. (To the reader: Why?) But if conceivability entails possibility, it would have to be possibly true and possibly false. This issue about conceivability and real possibility has led to an extended series of debates too complex to enter into here.”[17]
It could be the case that similarly disembodied existence seems conceivable but such a state of affairs has hidden contradictions, like rocks hidden in a pond, which might later be stumbled upon.
5. Objections and Rebuttals
For Swinburne, conceivability appears to mean that someone can understand the general features of the thought experiment and can visualize things or events in their mind. For this reason, Swinburne appeals to the fact that even young children, of even seven years of age, might comprehend and assess whether his thought experiments are coherent.[18] In response, I say that there can be thought experiments that are conceivable in this sense, but turn out to be incoherent upon further analysis. For example, one might imagine a married bachelor and visualize in their mind a particular man who is both married and a bachelor—however upon reflection about the contradictory nature of being ‘married’ and ‘bachelor’ it is seen that they are mutually exclusive categories and there is no such man as the one who was visualized.
A possible objection to what I have stated is to argue that humans are already intimately acquainted with consciousness and this is all that is required to be equipped to assess the coherence of the thought experiments in question without needing to be informed of the nuances of philosophy of mind. In response, I would say that there is more to consciousness than what anyone is conscious of. I do not think that having a phenomenal consciousness entails that we know everything about the composition and ontological status of it. Even supposing the substance dualist account is true, conscious experience presently involves my mind exercising influence over billions of neurons which fire constantly. I am not aware of the existence of neurons or the particular structures of the brain by conscious experience. If I have a pain, I know that C-fibers in my brain are being stimulated, but when a peasant in medieval Europe had a pain, he also had C-fibers stimulated in his brain, but he knew nothing of what C-fibers are or what neurons are. Which is to say, that there could be relevant aspects of the ontology of our phenomenal consciousness that we are not aware of.
6. Conclusion
While there are many considerations favoring arguments for the soul from the possibility of disembodied existence, such as persuasive and simple thought experiments, I think the argument relies too heavily upon the conceivability thesis to judge metaphysical possibility. I also think that the possibility premise is question begging, and could not be accepted by someone who is not already a dualist, hence the argument is epistemically circular. Any argument for the existence of the soul from the conceivability of scenarios of disembodied existence will have this problem because it will have a possibility premise similar to that in Swinburne’s argument which asserts the metaphysical possibility of existing without a body before reaching the conclusion that there is a soul.
Footnotes
[1] Richard Swinburne, The Evolution of the Soul, revised edition (Oxford: Clarendon Press, 1986), p. 323; Are We Bodies or Souls? (Oxford: Oxford University Press, 2019), p. 68-86.
[2] Nicholas Everitt, Substance Dualism and Disembodied Existence (Faith and Philosophy, vol. 17 no. 3, 2000), p. 333-347.
[3] William Hasker, Swinburne’s Modal Argument for Dualism: Epistemically Circular (Faith and Philosophy vol. 15 no. 3, 1998), p. 366-370.
[4] Richard Swinburne, The Modal Argument is Not Circular (Faith and Philosophy 15, 3, 1998), p. 371-372.
[5] Paul Tidman, Conceivability as a test for possibility (American Philosophical Quarterly 31 (4, 1994), p. 297-309.
[6] Jaegwon Kim, Philosophy of Mind. Third Edition. (Colorado: Westview Press, 2011), p. 39-47, 309.
[7] R. Swinburne, Evolution of the Soul (1997), p. 322-332.
[8] W. Hasker, Swinburne’s Modal Argument for Dualism (1998), p. 370.
[9] R. Swinburne, The Modal Argument is Not Circular (1998), p. 371.
[10] Ibid.
[11] J. Kim, Philosophy of Mind (2011), p. 39, 40.
[12] R. Swinburne, The Modal Argument is Not Circular (1998), p. 371.
[13] That is, that I might continue to exist after anything that is considered my body (or could potentially be considered my body) is suddenly destroyed as I am thinking, not by gradual replacement.
[14] Swinburne, Are we Bodies or Souls? (2019), p. 76, 77.
[15] D. J. Chalmers, Facing up to the Problem (1995), p. 15, 16.
[16] J. Kim, Philosophy of Mind (2011), p. 309.
[17] Ibid., p. 39, cf. 44-47.
[18] R. Swinburne, The Modal Argument is Not Circular (1998), p. 371, 372.
References
Alston, William (1986). "Epistemic Circularity" Philosophy and Phenomenological Research, Vol. 47:325-329.
Chalmers, David (1995). Facing Up to the Problem of Consciousness. Journal of Consciousness Studies, 2(3).
Everitt, Nicholas (2000). “Substance Dualism and Disembodied Existence.” Faith and Philosophy 17 (3):333-347.
Hasker, William (1998). “Swinburne’s Modal Argument for Dualism: Epistemically Circular.” Faith and Philosophy 15 (3):366-370.
Kim, Jaegwon. 2011. Philosophy of Mind. Third edition. Colorado: Westview Press.
Penelhum, Terence (1970). Survival and Disembodied Existence. New York: Humanities Press.
Swinburne, Richard (1998). “The Modal Argument is Not Circular.” Faith and Philosophy 15 (3):371-372.
Swinburne, Richard (1986). The Evolution of the Soul. Oxford, GB: Oxford University Press.
Swinburne, Richard (2019). Are We Bodies or Souls?. Oxford: Oxford University Press.
Tidman, Paul (1994). “Conceivability as a test for possibility.” American Philosophical Quarterly 31 (4):297-309.