The Case For (and Against) Life After Death (3): Kantian Dualism

As I have often argued on this blog, there is a fundamental opposition between Darwinian naturalism and Kantian dualism. 

When Darwin turns to the moral sense in The Descent of Man (in chapter 4), he indicates "that of all the differences between man and the lower animals, the moral sense or conscience is by far the most important" (Penguin edition, 120).  He then quotes from Immanuel Kant: "Duty!  Wondrous thought, that workest neither by fond insinuation, flattery, nor by any threat, but merely by holding up thy naked law in the soul, and so extorting for thyself always reverence, if not always obedience; before whom all appetites are dumb, however secretly they rebel; whence thy original?"  Darwin then writes: "This great question has been discussed by many writers of consummate ability; and my sole excuse for touching on it, is the impossibility of here passing it over; and because, as far as I know, no one has approached it exclusively from the side of natural history."

Darwin's quotation of Kant is from his Critique of Practical Reason (AA, p. 86).  Immediately after the quoted sentence, Kant says that moral duty shows us "man as belonging to two worlds"--a phenomenal world of natural causes and a noumenal world of human freedom.  Apparently, Darwin does not accept this Kantian dualism, because he proposes to explain moral duty "exclusively from the side of natural history," and thus he implicitly rejects Kant's claim that human morality belongs to a transcendental world beyond the natural world.

In her review of Darwin's Descent, Frances Cobbe complained that Darwin's denial of Kantian dualism and of the cosmic transcendence of human morality would promote moral nihilism.  She also worried that this would deny life after death.  If we were to carefully study people who are dying, she argued (in "The Peak in Darien"), we could see that some of them give us a fleeting glimpse of the transition from this world to the next world.

Like Cobbe, Dinesh D'Souza adopts Kantian dualism as the ground for his defense of life after death.  He is explicit about this both in chapter 9 of Life After Death: The Evidence and chapter 15 of What's So Great About Christianity (Regnery, 2007). 

D'Souza uses Kantian dualism to refute empirical realism.  "Empirical realism is based on a premise that many people would consider obvious: there is a real world out there, and we come to know it objectively through our senses and through scientific testing and observation.  This is sometimes called the correspondence theory of truth, because it presumes a correspondence between the real world and our sensory and intellectual apprehension of that world" (Life, 148).  He needs to refute this empirical realism so that he can argue that the empirical world--the world that we know by natural experience and reasoning--is not the only world, because there is a supernatural or transcendental world that is beyond the limits of reason.

He begins by asking what he takes to be the fundamental question for modern Western philosophy: "How do we know that the representations of reality that we have in our minds correspond to reality itself?" (Life, 149).  His Kantian answer is that we don't know this.  We have no way to prove that our subjective mental experiences correspond to the objective material world.

The fallacy of empirical realism, D'Souza contends, is the failure to see that there is a distinction between experience and reality, because the world as we experience it does not always correspond to the world as it really is.  George Berkeley was right: "The only things we perceive are our perceptions."  Our apprehension of the world depends upon our perceptual apparatus--our five senses and the cognitive system of our brains--which filters our experience.  Whatever cannot be captured by this perceptual and cognitive system cannot be known to us. 

So, for example, we known that dogs, bats, and bees have perceptual capacities beyond ours, and thus we cannot perceive what they perceive.  All animals are limited in what they can perceive by their sensory and cognitive apparatus.

From this, Kant inferred that we live in two worlds--the world as it appears to us (the phenomenon) and the world as it really is in itself (the noumenon).  Our reason is limited in that it knows the phenomenal world but not the noumenal world.  Kant argued for this limit on reason as a way to create room for faith, and this is what D'Souza finds so attractive: Kantian dualism supports religious faith in a transcendent reality that is beyond empirical realism.  If "human reason can never grasp reality itself" (Christianity, 173), as D'Souza says, then human reason cannot judge religious belief in the reality of a transcendent, supernatural world.  "We learn from Kant that within the domain of experience, human reason is sovereign, but it is in no way unreasonable to believe things on faith that simply cannot be adjudicated by reason" (D'Souza, "What Atheists Kant Refute").

In response to Daniel Dennett's claim that many people have refuted Kant, D'Souza answered: "In fact, there are no refutations" (Christianity, 174).  So Kant cant be refuted?  Is it irrefutable that "human reason can never grasp reality itself," that we "see things in a limited and distorted way," and that our "minds have a built-in disposition toward illusion"?

On the contrary, far from being irrefutable, Kant refutes himself.

Consider the following remark by D'Souza: "There are things in themselves--what Kant called the noumenon--and of them we can know nothing.  What we can know is our experience of those things, what Kant called the phenomenon" (Christianity, 171).  How do Kant and D'Souza know this?  If "we can know nothing" of things in themselves, then how do Kant and D'Souza know that there are things in themselves, and that these things in themselves are different from our experience of those things?  If "human reason can never grasp reality itself," then how can the human reason of Kant and D'Souza grasp the reality of the distinction between the noumenal and phenomenal worlds?  Isn't their argument self-refuting?

Kant and D'Souza are sophistical in assuming that by refuting a naïve realism they have refuted empirical realism.  It is naïve to believe that what we know by experience and reason always corresponds exactly and fully to reality.  Of course, our experience and reasoning are fallible in their grasp of reality.  But from that it does not follow that we can never have any grasp of reality in itself.  We can correct the mistakes of our experience and reasoning to strive for an approximate correspondence to reality.  So, for example, we can discover the limits of our sensory apparatus, and we can see that other animals have sensory capacities that we do not have.  We can use our cognitive capacities to infer how the world looks to dogs, bats, and bees.  We can also infer the existence of subatomic particles that are not directly accessible to our senses.  This is what science does.

Moreover, we can see that having evolved for life on earth, we are naturally adapted in our sensory and cognitive capacities for gathering information about our world and responding to it in adaptive ways.  If our mental models of the world had no correspondence to that world, and if we were unable to correct those models to make them correspond at least approximately to that world, we could not have survived and reproduced.

Through our experience and reasoning, and with the assistance of science, we need to probe ever deeper into the inexhaustible depths of the natural world, so that as we reach new levels of reality, we see new mysteries that raise new questions.  There is no need, as Kant and D'Souza insist, to assume that this wonderful world of nature is an illusion that hides the real world that can only be reached by denying reason and experience.  We were not thrown into this natural world from some other world far away.  This natural world is our home because we are naturally adapted live in it and investigate its wonders.