by Professor Peter Kreeft
From a lecture series given in 2006, transcribed 2023
Hindus and Buddhists accept reincartion on grounds of religious authority, and Christians, Jews, and Muslims reject it for the same reason; but there are also arguments for and against reincarnation that do not depend on faith or religious authority, but only on reason.
I think there are three main arguments for reincarnation.
The first argument is actual data. People often remember past lives, or claim to. Most of the time this is probably imaginary, and often silly. People almost always claim to have been someone famous or interesting. If all the claims are true, then almost everyone must have been a king or a queen, and no one was ever a slave. But sometimes the claims seem credible — when people claim to remember past lives in detail and sometimes the details check out — such as the location of hidden treasures. These cases are rare but they do exist. Can they be explained without reincarnation? Probably — as something like a racial memory or a collective unconcious or even mental telepathy with the dead — with ghosts who transfer their knowledge of these details into the minds of the living. By the way there is an surprisingly large, diverse, and scientifically credible heap of evidence for the existence of ghosts, and there are sober scientific organizations that study such phenomena, such as the British society for Psychical Research.1
A second piece of evidence for reincartion is not one that can be checked empirically, but it's very common and apparently very wise. It's a premise about self-knowledge. Only unwise people, only shallow and arrogant people, who don't know themselves, can believe that they're perfect. Most of us know that even if our lives have been quite full and satisfying, we're not perfect. We're not as good or as wise as we could be. Even the best of us, especially the best of us, say we're fools. Only fools say they're wise, and only great sinners say they're saints. The wise know that they're fools, and the saints know that they're sinners.
Now, when we die, we're yet done. We're not yet fully cooked, so to speak. We're not all that we can be. There's a great gap between the actual and the potential, between the real and the ideal. Only if we vastly overestimate our actuality or vastly underestimate our potentiality can we deny that great gap. Now even those who don't believe in reincarnation usually agree with both sides of this premise — the gap between what we are and what we ought to be. One side could be called hope and the other humility. The wiser and the better we are, the more of both hope and humility we have — that is, the more that we believe that we are called to be something utterly glorious and saintly and wise, something of which we catch only brief glimpses in this life, and therefore we feel humble, judged by that high ideal.
Well, that is a profound premise, but it doesn't prove reincarnation. Reincarnation does explain and justify this deep insight, yes, but I see no way of proving that reincarnation is the only way of justifying it. In fact it might be argued that reincarnation is a rather unimaginative way. It realizes we have a long way to go, but it says that the road ahead is only more of the same, more segments of the road behind. According to reincarnation the gap between what we are and what we are called to be is closed by an addition of quantity, not quality — by more lives of the same kind in the same world in the same sort of body.
Aren't there other and better ways to close the gap? Wouldn't it be more in line with all the analogies in life to believe in some sort of body and world and experience after death that is radically different than this one, as this world is different than life in the womb, rather than just another bigger and better womb? Life doesn't seem to be a series of repetitions but a series of births, or like multi-stage rockets — the old stage falls away like the placenta after birth and the next stage flies into new and higher skies and among new trajectories.
Imagine three unborn babies arguing about life after birth. One says it's a myth, the second says it's real and consists of bigger and better wombs, and the third says it's real and almost totally unimaginable. And we all know the third one is right. Well, isn't it reasonable that we are like those babies, the universe is like a womb, and death is like birth? Obviously we can't prove that, but signs seem to point that way — you can't "go home" again. Since birth is the only experience we've ever had that is as radical as death, and seems similar to death in many ways, it seems to be a likely parallel. If so, it's the third baby who's right — neither the first, the materialist, nor the second, the reincarnationalist.
But a third argument for reincarnation is that if a soul is a different kind of thing than a body, as a person is a different kind of thing than a house, then a soul could enter and leave various bodies like houses — and not just one. If the individual soul is confined to one and only one body and can't reincarnate into others, then it seems the soul really isn't a free and independent spirit, like the guest who is free to change hotels.
But is the soul that independent? I think the main reason materialism is credible is all the evidence that the soul is not that independent — if I knock your brains out I stop you from thinking. We don't think of ourselves as guests in hotels or ghosts in machines. We can't take our bodies off as we can take our clothes off. We are our bodies as well as our souls. The soul would be to the body something like the meaning of a book would be to the words of the book, or the essence of a work of art to the matter it's made out of. We experience our soul and our body not as two things, but as two aspects or dimensions of this one concrete thing we call ourselves. So reincarnation would seem to contradict the basic principle of psycho-somatic unity, the oneness of soul and body, which is a good principle of psychology and common sense.
A fourth argument for reincarnation is that it does you good to believe it because it conquers your natural fear of death and your obsession with your body and your body's goods. So it's a sort of Pascal's Wager type of argument. It can't be disproved, and it's got a payoff. But the payoff comes in this life rather than the next. You lose nothing, and you gain much by believing it. You gain detachment from the body's goods and evils especially the greatest bodily evil, death. The problem though is that the price it has to pay is a very low view of the body, as an illusion, or a temptation, or a prison cell, or at best a mere temporary container, or hotel or moral gymnasium.
There are other problems with reincarnation though such as the number of souls. There's been an enormous population explosion in the last few centuries. More people have lived and died in the last two to three centuries than in the previous thirty or forty. Where did all those new souls come from?
Another problem is an apparent built-in self-contradiction. Reincarnation is not forever. Once you're sufficiently pure and wise and good, once you're fully cooked so to speak, you're out of the oven, free from bodies forever, and you can go to heaven. Now, that heaven has to be perfect, otherwise it wouldn't be your goal. But if heaven is perfect, there's no evil in it. So far so good. But when we trace our series of reincarnations back instead of forward, to the first one, we come to this question: why did I need this whole series of bodies in the first place? If bodies are like reform schools, what sin did I commit to merit being placed in the first reform school? I must have committed some sin in heaven to merit being sent down to earth into my first prison cell, my first body. If my being sent down here was just, then I must have sinned in heaven, and then heaven isn't so perfect after all, so why should I want to go back there? And if it was unjust, if my being sent down was not deserved that's even worse because then there's injustice and sin not just in men but in the gods.
Still another problem with reincarnation is a psychological one. We don't usually remember our past lives, so how can we be said to be the same person as the one who once had another body if there is no continuity of memory? Supposedly reincarnation is necessary for educational purposes — we need new bodies and new lives to learn the lessons we failed to learn in the last ones. But how can anybody learn from their mistakes if they don't remember their mistakes?
Perhaps these questions have decent answers, but I have neither the time nor the expertise to consider them, so I will have to leave the question open.
1 It should in fairness be pointed out that the work of the British Society for Psychical Research has, if one believes Wikipedia, largely been debunked. Professor Kreeft might not have been aware of this.