One simple but at least superficially compelling argument against an afterlife that I once heard and entertained myself for some time is that no-one ever came back from the dead to report on what they saw. Reading Dutch cardiologist Pim van Lommel's book on near-death experiences and the nature of consciousness, Eindeloos bewustzijn, I realized the circularity of the argument. Because it is extremely hard to pinpoint exactly when death occurs. When our heart stops beating? When we cease to breathe? When electrical activity in the brain ceases? And, of course, parts of me are dying (and, hopefully, being replaced) all the time. Of course, we could define death as the cessation of personal experience, but this would be question-begging with regards to the issue of an afterlife. Now, a fair number of people appear to have personal experience (of some kind) in a situation when some hallmarks of physical death are already present - van Lommel's research would indicate near-death experiences may occur in some five percent of heart failures, or even a little more. But the very term "near-death experience" suggests that we tend to assume they have not yet "really" died in such cases. In any event, the argument against an afterlife seems to me much more circular and question-begging than it once did.
Pim van Lommel's well-written book combines a survey on the current state of NDE research (with a lot of personal testimonies) with a speculative hypothesis on the nature of consciousness. Van Lommel rejects neurophysiological explanation of NDE's (such as a hallucination in response of hypoxia, etc.) as it is difficult to account for hallucinations with the minimal or absent brain activity some people experiencing NDE's yet have. Van Lommel also mentions the enormous, life-changing impressions these experiences seem to leave. Finally, there may be an argument from the similarities across various NDE's. The cigarette I just lighted and am smoking now may be a hallucination. But the world, including other people, seem to be very much coherent with the notion that I am smoking a cigarette. They act in accordance with it. And ultimately, part of my warrant for believing what I'm seeing comes from other people believing the same (or acting as if they do). They of course may be hallucinations themselves, but let's not go there.
Van Lommel's survey contains many fascinating details. The sensory experiences people report from the other side seem to be not quite sensory, or almost akin to synaesthesia: colours are 'felt', rather than seen, etc. Especially striking is a drawing by a six-year old girl of a near death-experience, depicting her smiling and flying at apparently great speed over an operation table where her not-so-happy looking double is attended upon by two doctors. A curious detail is a little row of angels in the upper right-hand corner of the drawing, complete with aureoles and all. I very much doubt that the child actually saw angels with actual aureoles. Perhaps she gained a notion of "heaven" and drew the angels because, of course, that's where the angels are; or alternatively, she may have met people or beings who she interpreted as being angels. The latter possibility points to a problem in interpreting NDE's. Provided they are genuine experiences of a genuine reality, this reality may be so numinous or so alien that it becomes extremely difficult to describe without resorting to more familiar notions.
Van Lommel's speculative notions of consciousness are based, unsurprisingly, on quantum mechanics. I have no real problem with that, though I am of course aware that a lot of ideas concerning consciousness and quantum mechanics are a bit fuzzy, to say the least. But part of this surely results from the fact that quantum mechanics does genuinely point to a relationship between consciousness and matter which sits ill with more causally-based, materialist notions. Van Lommel is careful enough to point out that the interpretation of QM he chooses to follow is controversial, and bases himself on the work of such researchers as Roger Penrose and Stuart Hameroff, Henry Stapp, etc. I'm aware of a lot of his sources and his treatment seems pretty competent to me - nonetheless, the sections on QM and consciousness are very, very dense at times. The problem here is precisely that experiments such as the double-slit experiment, or Alain Aspect's work on entangled pairs, do point to an underlying reality that is very, very weird. Books do not come in unlimited sizes, and Van Lommel's is hefty enough as it is, but this is one part where perhaps a little more time should be spent on making clear precisely why the picture of reality Van Lommel presents is so shocking.
This said, I find the picture in broad outline not unbelievable. Van Lommel defends a largely panpsychistic (or panprotopsychistic) idea of mind and matter in accordance with Chalmer's type-F monism: matter and mind are double aspects of the same underlying reality. As for NDE's, Van Lommel believes they tap into some kind of "non-local" underlying realm of spirit - perhaps akin to Whitehead's notion of the consequent nature of God (where possibilities or eternal objects are perpetually entertained, and which at the same time functions as the "memory" of the universe, to which every single event that has ever happened remains for ever present and manifest). Through intermediaries such as Sheldrake, Henry Stapp, Ervin Laszlo and the like, the influence of such figures as Whitehead, Peirce, Bergson and William James is accounted for.
No singular scientific observation can falsify philosophical materialism (or any other metaphysical notion of mind and matter). It's certainly possible that accounts of NDE's are indeed based on hallucinations, dreams, imperfect recollection, etc. On the other hand, metaphysical notions are certainly not impervious to empirical science. NDE's are just another part of a body of largely anecdotical and some statistical evidence that is hard to account for within a physicalist world-view (Van Lommel refers to quite a bit of it near the end of his book). Taking all of it together, there is a case for taking things exactly as they seem to be: that NDE's are indeed experiences of some kind of reality that awaits us all after death; that instances of extrasensory perception are indeed instances of extrasensory perception, etc. The task then becomes to propose a coherent world-view which is able to account for these notions. Van Lommel's valiant attempt is highly speculative and probably wrong in the honourable way that grand, speculative visions tend to end up being. But I think there's a chance that parts of it, and perhaps even big parts, may actually be correct.
I have very few set beliefs on an afterlife. I would tend to reject notions of an afterlife as "everlasting" rather than "eternal": as a temporal sequence which never ends. The idea seems at times even horrible to me. When I started to take the possibility of God's existence seriously some years ago, I refused to mentally touch the issue because I was afraid that my very vivid and very present fear of death would prejudice me. For quite some time, I entertained a Whiteheadian notion of "objective immortality": my life, and my thoughts, sensory impressions, etc. would remain forever present to God, though there would be no personal survival of consciousness in the works. At the same time, I began to entertain more eschatological notions (the resurrection, etc.) at least as an object of hope.
Currently, I don't know what to think. Van Lommel tends to reject the notion of reincarnation in favour of the notion that "remembered" past lives may be the remembered lives of others, and I would agree with that. I suppose I am torn between the "prophetic" pole of Christianity with its promise of a Kingdom of God and a perhaps very physical resurrection at the end of times; and the more "mystical" pole of philosophical idealisms, Whitehead's notions of process philosophy, etc. For this reason, I am not sure how to take Van Lommel's book. Perhaps for the moment I'll take it as a compelling argument that we, as centres of experience, feeling, consciousness, are after all quite at home in the universe.