John Gfoeller has posted a response to my post about the Buddhist doctrine of rebirth. The substance of our debate is whether the Buddhist view is compatible with scientific naturalism; I argue that it is not.
John makes a number of points, and I don't know if I will have time or space to reply to them all, at least for now. (I still have yet to reply to all of the points he made on his first post, and here I am commenting on his second!)
The first point John makes is that there is diversity in Buddhists' interpretation of the doctrine of rebirth. He concludes that the Buddhist doctrine of rebirth can be interpreted in a way that is consistent with the worldview of scientific naturalism. I accept his premise, but deny his conclusion.
In other words, all Buddhists are required to accept the teaching of rebirth, but Buddhists seem to interpret that idea in different ways. Therevadans and Secularists seem to have the most strict view of no-self (anatman). Some Mahayanists and the Tibetans have the least emphasis on anatman — to the point where I wonder aloud if they really believe in a permanent self in everything but name. And there are views between those two poles.It is true that Theravada and Mahayana Buddhists vary in their interpretation of both the no-self and rebirth doctrines. I should first note that there are secular Buddhists rooted in both Theravada and Mahayana Buddhism, so I don't think it is correct to imply that they are necessarily closer to the Theravada view on these issues.
In terms of the no-self doctrine, many Mahayana Buddhists accept the notion of Tathagatagarbha or Buddha Nature, which, depending on the interpretation, is either simply the potential all beings have to become enlightened, or a sort of substantial Buddha principle present in all beings. The latter interpretation of Tathagatagarbha does seem in tension with the no-self doctrine (anatman), because it makes the Buddha Nature into a kind of cosmic self similar to the Hindu notion of Atman. But the interpretation of Tathagatagarbha is a separate issue from the interpretation of the doctrine of rebirth. Rebirth neither entails nor is entailed by Tathagatagarbha.
In terms of rebirth, both Mahayana Buddhists and Theravada Buddhists agree that there are karmic links between the ephemeral states that make up a "person" across different lifetimes. I put the term 'person' into scare quotes here because, according to Buddhists, the person can only be said to exist when using a conventional level of discourse, in which the continuity of the person is understood not in terms of a single persistent substance, but rather as a matter of the degree of relatedness of different physical and psychological states; at the ultimate level of discourse, persons do not exist, only metaphysical atoms (from the Theravada point of view, as described in the Theravada Abhidhamma) or the indivisible flow of emptiness or shunyata (from the Mahayana point of view, as described for example in Nagarjuna's The Fundamental Wisdom of the Middle Way).
The Mahayana interpretation of rebirth (in fact, there are several) is not influenced solely or even primarily by the Tathagatagarbha doctrine. A bigger influence is the Mahayana doctrine of seed or store consciousness (which is supposed to be what provides the metaphysical connection between a karmic act and its fruit). But the key issue with respect to the doctrine of rebirth is whether there is significant causal connectedness between the conscious states of organisms across different lifetimes, and on this view Theravada and Mahayana Buddhists are in complete agreement. Secular Buddhists from both traditions may attempt to deny this interpretation of rebirth, but in doing so they are making a radical departure from tradition, and in effect denying rebirth altogether.
Put more formally, then: How to interpret the mechanism by which the causality of contingent consciousness operates in Buddhist theory? On the one hand, all Buddhists believe that consciousness is caused by other moments of consciousness; in other words, consciousness is the anatman because it is contingent upon a complex process of dependent origination. On the other hand, all Buddhists believe that the mechanism for that process is rebirth through (at least) five different states of reality / consciousness: gods, man, animals, hungry ghosts, demons. How to interpret all that? How to reconcile the two a priori Buddhist beliefs of no-self and rebirth?I attempted to explain in my previous post how Buddhists reconcile no-self and rebirth. The key is to realize that no-self is just as difficult to reconcile with the continuity of a person within a single lifetime as it is to reconcile with the continuity of a person between lifetimes. In both cases, the metaphysical glue which holds the transient physical and psychological states together into a conventional person is: karmic causation. This is true both from the Mahayana and the Theravada points of view. What makes the future person the same as the past person (from a conventional point of view) is that the karma of the particular past states in question leads to fruit which is experienced in and through the particular future states in question.
Again: The answer seems to be in different emphases in understanding rebirth itself. Theravadans and Secularists seem to deemphasize rebirth into other forms of consciousness. Theravadans (at least, in the monasteries) acknowledge rebirth in other realms of existence, but they instead emphasizes enlightenment in this lifetime. Secularists either reject the other realms or interpret them as metaphors for psychological states of awareness in this life; and either way they emphasize Dhamma as a philosophy and enlightenment as a possibility — in this life. Some Mahayanists and the Tibetans seem to greatly emphasize rebirth in other states of reality / consciousness. I mention again the Pure Land sect (and the Tibetans) as virtually believing in a permanent self (that reincarnates) in everything but name. And, again, there are points of emphasis in between these two poles.It's true that secular Buddhists are more likely to radically reinterpret the doctrine of rebirth, precisely because it is inconsistent with the modern scientific worldview, but a reinterpretation of rebirth which denies karmic causation across lifetimes amounts to a denial of the doctrine, not merely an alternative interpretation of it.
I should note that only some Theravada Buddhists emphasize enlightenment in this lifetime; traditionally, very few did, and many Theravada Buddhists still deny that enlightenment is even possible in the current state of the world. The Theravada interest in intensive meditation practice, which may have been the source of John's view about their focus on enlightenment in this life, has only become strong again since the late 19th century (the website Access to Insight has a lot of useful information on the recent history of Theravada Buddhism; another useful work is Richard Gombrich's classic Precept and Practice, which is about the history of Theravada Buddhism in Sri Lanka). Theravada Buddhists, even the ones who practice meditation intensively, perhaps with the intention of achieving enlightenment in this lifetime (which is not always the case among ardent meditators, whether Theravada or Mahayana), believe in rebirth just as much as do Mahayana Buddhists. John seems to assume that the more one believes in rebirth, the more one must believe in a soul or self which is reborn, but as I have tried to indicate, on the Buddhist view this is just not the case. The Pali Canon is adamant both in its denial of all forms of self or soul theory, and in its denial of annihilationism, which is the view that the person ends absolutely at death. The mechanism for the continuity between lives is karma, not a soul, and this is so both from the Theravada and from the Mahayana point of view.
Therefore, while all Buddhists must accept the idea of rebirth, there is substantial variety in Buddhism for interpreting that idea.This is true, but it does not prove that the doctrine of rebirth on any of its interpretations is consistent with the worldview of scientific naturalism, which is what John was seeking to establish. And I have tried to show that the notion of karmic causation across lifetimes, which is inconsistent with scientific naturalism, is what all of the interpretations of the doctrine of rebirth have in common.