There has been a surprising amount of effort expended over more than a hundred years to scientifically establish the reality of life after death. Yet, while a great deal of evidence has been collected, it falls short of providing absolute proof. At best it suggests a very strong probability of life after death, but it has not clinched the case. Why?
Some would argue that absolute proof is rare in any empirical investigation. Science generally operates in terms of probabilities, not absolutes. The philosopher of science Karl Popper went so far as to say that no theory can be proven true; theories can only be falsified, i.e., disproven. If a theory survives concerted attempts at falsification, it may be provisionally accepted as true, but there is always the chance it will be falsified later.
But while abstract theories may not be provable, empirical facts are. And one would think that life after death, if it is real, would constitute an empirical fact and would therefore be susceptible of proof.
Of course, some facts are easier to establish than others. An afterlife, by its nature, would be extremely difficult to prove simply because it presumably exists on a different "level" or "plane" of reality than the one we presently inhabit. It would not be "empirical" in the same sense that a rock or a tree is empirical. But I think there's more to it than that.
Actually, I have started to think it is probably impossible, even in principle, ever to obtain objective proof of life after death. Note that I am talking not about evidence, which is abundant, but about conclusive proof, which remains elusive and perhaps always will.
I could be all wrong about this. These are relatively deep waters, and I may be out of my depth. My perspective depends on the very tricky distinction between objective and subjective, a distinction that has bedeviled people who are far more philosophically sophisticated than I am.
Nevertheless, for what it's worth, here's what I've been thinking.
First, what do we mean by "life after death"? Ordinarily, at least in Western culture, we mean the survival of the individual as an individual. Absorption into some undifferentiated cosmic Oneness might be a kind of life after death, but it's not what we typically are talking about.
But what is the individual? Clearly, in this context, we mean the unique consciousness of a particular person — the "I," or sense of self.
And here's the rub. Consciousness, by its nature, is a subjective state.
The only consciousness we know directly is our own. Strictly speaking, we cannot be absolutely sure — we can't prove — that other people are conscious. We observe their behavior, and from it we infer consciousness. To put it another way, we know that our consciousness directly influences our behavior, and so we assume that other people's behavior has its origins in their consciousness. And this makes sense. It's a perfectly plausible inference … but still only an inference.
Since we cannot know someone else's consciousness first-hand, we can only rely on other people's statements about their inner state, and on extrapolation from our own personal experience. In short, we draw an "inference to the best explanation."
I'm not denying that this is, in fact, the best explanation. I don't doubt that other people are conscious. I'm only pointing out that we can't access other people's state of being, just as they can't access ours. Consciousness is inherently subjective. As such, it resists any attempt to prove its existence objectively.
Note that this is the case even in the case of ESP. Impressions plucked from someone else's mind are known to us only because they appear in our particular field of consciousness. We still cannot experience the other person's consciousness, his sense of self.
Now, if this is true regarding other human beings who are alive and interacting with us directly, it would be even more true of discarnate beings accessible to us only through an altered state of consciousness or through some intermediary, i.e., a medium. We can't prove that the subjective state of consciousness operates in other living beings, and we can't prove that it persists in those who are no longer physically alive. The best we can do is find pointers that imply such a conclusion — pointers that make the inference more plausible.
If information coming through a medium is specific, detailed, and likely to be known only to us and to the deceased person who is allegedly communicating, and if hints of that person's distinctive personality also come through, then we may very well feel justified in concluding that our deceased friend really is conveying a message to us. This is arguably an inference to the best explanation, if other possible explanations, such as conscious or unconscious fraud and self-delusion, are ruled out. But it still isn't proof in any absolute sense. It can't be, because objective proof of the reality of a subjective experience is impossible, and the discarnate being's consciousness (like all consciousness) is subjective.
We may just have to accept the fact that no objective proof can actually be attained in this area. The best we may be able to hope for is that we personally become convinced by our own experiences, but not that we can convince others who have not shared our experiences.
I'm not sure this matters very much, since the purpose of life is not convince others to agree with us. But those who are hoping for some slam-dunk, irrefutable, objective proof that will render all skepticism obsolete may be dreaming an impossible dream.