In the second noble truth the Buddha clearly presupposes the doctrine of rebirth conditional on past karma. The Hindu tradition is also committed to a comparable belief from the time of the earliest Upanishads onwards. But how important is this doctrine for members of these two religious traditions today, and how might it be interpreted to illuminate our current understanding of embodied cognition? These questions will be discussed in this article.

We begin by considering the extent to which Buddhist and Hindu scientists believe in the doctrine of rebirth, and how they interpret it. The following investigations were carried out by the author, and the Hindu data has recently been reviewed and found to be broadly consistent with the original material.

Buddhism and Rebirth

Thai Buddhism is distinctively Thai, and although it cannot be assumed that Buddhists in other Theravada countries such as Sri Lanka will share the same ideas, there is no reason to suppose that they are significantly different. A brief account of the author's research in Southeast Asia is contained in Religion and Ecology in India and Southeast Asia (Gosling , 68–103). Details of the investigation into rebirth among Thai Buddhist scientists are summarized in an article in the Southeast Asian Journal of Social Science (Gosling ).

Buddhists, unlike Hindus, do not believe in a transmigrating entity often described as a soul. This distinction is denoted by the cardinal Buddhist doctrine of anattā (Pali—corresponding to anātman in Sanskrit). Since there is no subsistent reality to be found underlying appearances, there cannot be a subsistent self or soul in the human appearance. If all is subject to dukkha (transience and associated grief), then human appearance is no exception. The five aggregates (khandhas) that flow together and give the impression of identity and temporal persistence constitute each and every human being. Beyond death, these five components of personhood are reconstituted according to the continuity of consequence, governed by kamma.

Bearing in mind the range of interpretations covered by different Buddhist schools, we might clarify our reference to the lack of subsistent reality underlying appearances by stating positively that the reality underlying appearances is one of a continuously changing interaction of impersonal constituents (i.e., dhammas). The final or absolute reality in terms of these dhammas is the subject of debate in the broader Buddhist tradition, but insofar as this picture affects the status of the “self,” the Buddhist tradition seems unanimous. (We are not concerned here with the historical discussion of the Pudgalavādins and Sammatīyas.)

The Buddhist view has implications for our understanding of the extended mind because it enlarges the time scale of human existence and adds a moral dimension based on the four noble truths. But popular Buddhism—especially in Thailand—often diverges considerably from its scholastic counterpart, and the impact of science has influenced the extent to which modern Buddhists maintain belief in cardinal doctrines such as rebirth.

Predominantly young scientists at five secular universities and one Buddhist one in Thailand were asked to complete a Thai questionnaire that included a question about whether or not they expected to be reborn at death. Two hundred and eighty‐four questionnaires were completed and returned and seventy‐eight interviews were personally conducted; responses were analyzed and cross‐tabulated in accordance with the Statistical Package for the Social Sciences Program (SPSS) using the Chulalongkorn mainframe computer.

The universities (with acronyms) and their characteristics are as follows. Chulalongkorn (CHUL) is the “royal” university in Bangkok—traditional and elitist; Mahidol (MAHL), also in Bangkok, is for medical students—courses are longer and a high proportion of its members are Sino‐Thai; Kasetsart (KAST) is an agricultural university on the outskirts of Bangkok. To the north are Chiangmai University (CHNG) and Payap College (PAYP), the latter having been founded by Christian missionaries. These are essentially secular institutions, but Mahamakut University (MKUT) is exclusively for monks primarily from the Dhammayut order. (The corresponding university for Mahanikai monks is Mahachulalongkorn University, but there is not a lot of difference between the two orders.)

The questionnaire results are given in Table  (Gosling , 8).

There were problems over questionnaire distribution at Thammasat University, and those results have been omitted. Otherwise the calculation of chi‐square for six degrees of freedom was 39.25, which is a strong indication of the statistical validity of the results of the investigation. In all cases questionnaires were distributed and collected by faculty members during lecture or seminar periods, so the proportion of responses was extremely high.

The majority of respondents at Mahamakut University believed in rebirth (94%), which is not surprising since they were all monks. Interpreted interviews indicated that although a small minority (6%) did not believe in rebirth after death, they were able to interpret the doctrine as a moment‐to‐moment process in this life.

The Chulalongkorn percentage (34%) may be inflated because 17 members of the Buddhist Society, all young scientists, were included in the sample, and were not typical of the university population as a whole. Otherwise, on average, less than a quarter of young Buddhist scientists at Thai universities appear to believe in rebirth beyond death, the lowest proportion (14%) being at the medical university (Mahidol). Interviews clearly indicated a variety of reasons why Thai medics reject both rebirth and religion as a whole. The following comments by a Mahidol lecturer in molecular biology are fairly typical of this group:

At school you tend not to think seriously about religion at all and then you become an undergraduate and a graduate and find it more difficult to be religious. Religion to me implies faith but to be a scientist requires skepticism.… I find it very difficult to understand how a person can be truly scientific and at the same time religious. (Gosling , 12)

The dean of graduate studies said that he had become critical of Buddhism because he had felt as a young doctor that it sanctioned a passive attitude towards illness, and Dr. Yongyuth Yuthavong, a young and well‐known Mahidol medic, maintained that very few educated Thais were critical enough of Buddhism (Yuthavong , 207). But many respondents accepted rebirth beyond death as a cardinal Buddhist belief.

Figure summarizes the main features of the Buddhist understanding of rebirth.

The five khandhas are in a constant process of change and do not constitute a self (hence anattā). The concept of paṭicca samuppāda (dependent origination) determines the kammic continuity of consequence that extends into the next life and governs the reconstitution of the five khandhas. No entity transmigrates between this life and the next.

The Hindu Tradition and Rebirth

Whereas Buddhists reject the notion of a transmigrating entity often described as a soul, most Hindus from the Common Era onwards have believed that a trans‐empirical substrate of the individual self, known as the liṅga‐śarīra, survives bodily death. Within this substrate the accumulating karma of an individual karmic chain determines the characteristics of the next existence. It is sometimes also called the sūkṣma‐śarīra or subtle body, and is essentially a mechanism for storing and transferring accumulated karma from one life to the next. The notion of liṅga‐śarīra makes it possible to allow for a time‐lapse to occur between death and rebirth in the soul's search for an appropriate body to inhabit. (It also allows for offerings to be made that will improve the prospects of the soul before re‐embodiment.) “Self” or “spirit” is usually denoted by ātman.

There are dualistic and non‐dualistic Hindu schools that propose variants in understanding karma and rebirth. But they mostly agree that death involves the destruction of both the physical body and the mental ego (i.e., our distinctive sense of “I‐ness”). In the chain of rebirth that endures beyond each death, ātman is conjoined to the subtle body (liṅga‐śarīra), and this latter identifies a particular series of existences linking successive births. The subtle body is a natural substrate that is not susceptible to sense experiences, and is the repository of the accumulating karma and memory traces of a particular karmic sequence.

Thus the memory plays an important role in the rebirth process, and it is primarily this that determines our identity (i.e., what makes “me” the same person) in another existence.

We shall say more about this presently. However most Hindus are unaware of the ramifications of the basic notion of survival beyond death, which they perceive as increasingly questionable as they learn more about science. Studies were conducted at four major university centers in India by the author on the effects of science on the religious beliefs of scientists. These were wide‐ranging, but included an item that related to reincarnation. The data is summarized in Science and the Indian Tradition: When Einstein met Tagore (Gosling , 102–29).

The four investigation centers were Delhi, including the Indian Institute of Technology (IIT) and two colleges of Delhi University (St. Stephen's College—where I taught physics in the 1990s—and Miranda House, which is for women), Bangalore, where a lot of time was spent at the postgraduate Indian Institute of Science (IISc), Kottayam, and Madurai. Madurai was selected because its colleges contain predominantly non‐Brahmin Hindus (as opposed to the IISc); Kottayam is also distinctive. Seven hundred out of eight hundred questionnaires were completed, and 155 interviews were personally conducted. The results were processed using the IBM 360 computer at the IISc.

The percentages of scientists who experienced conflict or no conflict between science and religion in relation to reincarnation are given in Table  (Gosling , 111).

From Tables  and it appears that university‐based Hindu scientists are significantly more willing to believe in rebirth than their Buddhist counterparts. But many are not, as the following quote from a young woman scientist at Miranda House, Delhi, indicates:

I have rejected religion since doing pre‐medical studies.… It is wrong to think that good parents will have children and bad parents will be denied children by God. It just isn't true. Genetics determine what sort of children you have and not God.

The following examples illustrate the range of views expressed by Hindus from different backgrounds:

I feel that people do not always get what they deserve—some good people have a hard time as though something done in a previous existence might be responsible. (Nambūdri Brahmin at the IISc)

Science permits reincarnation.… Religion does not permit such artificial scientific methods [as birth control]. Controlling birth may mean controlling someone's reincarnation. (Arya Samajist at the Delhi IIT)

I believe in rebirth. In the Gītā, Krishna says, “In every age I come back.” (Hindu at the IISc)

Scientific training has modified my beliefs and the idea of rebirth has been discarded first. (Ramakrishna Mission member at the IISc)

Reincarnation is not possible; when you're dead, you're dead. (Hindu at the IISc)

A more detailed account of modern Hindu understandings of reincarnation, especially during the nineteenth century when major reformers such as Ram Mohan Roy, Swami Vivekananda, and Sri Aurobindo were active, is given by the author in a recent issue of Zygon (Gosling ). It is interesting to note, in passing, that Ram Mohan Roy, considered by many to be the father of modern India, did not believe in rebirth at all. In this he may have been harking back to an early Hindu group, the Cārvākas, who rejected reincarnation, caste, and belief in God altogether. They were considered unorthodox, but Hindu nonetheless.

Figure summarizes the main features of the Hindu understanding of rebirth.

The subtle body, which is characterized by prakṛti or nature, carries over into another life, with or without a pause, and identifies an appropriate birth according to its accumulating karma and memory traces.

Rebirth and Embodied Cognition

According to Stephen Batchelor,

It is often claimed that you cannot be a Buddhist if you do not accept the doctrine of rebirth. From a traditional point of view, it is indeed problematic to suspend belief in the idea of rebirth, since many basic notions then have to be rethought. But if we follow the Buddha's injunction not to accept things blindly, then orthodoxy should not stand in the way of forming our own understanding… Dharma practice can never be in contradiction with science: not because it provides some mystical validation of scientific findings but because it simply is not concerned with either validating or invalidating them. Its concern lies entirely with the nature of existential experience. (Batchelor , 36–37)

David DeMoss partially agrees with this, linking it to his understanding of the extended self‐model as follows:

If a contemporary interpretation of karma is [a] less metaphysically ambitious claim that past actions condition your future, then the extended self model can add useful insights about why this is so. As agent‐world circuits are established, the extended person itself is changed, and the new couplings may engender new cravings as well as new patterns of reasoning and behavior. This insight can, and should, influence praxis: be mindful of that with which you couple. Thus a pragmatic metaphysical reading of the four noble truths, and of craving as the origin of suffering in particular, need not get bogged down in the metaphysics of rebirth and karma. (DeMoss )

DeMoss proceeds to evaluate Buddhist craving within the context of the extended model of the self. Thus, craving is itself an extended process, and the extended model of the self may be used to interpret it as a function of agent‐world circuitry, rather than the inner drive of a core self. Just as the extended self is empty, so are its cravings. Furthermore, craving is a desire rooted in ignorance, the illusion of a fixed self, that leads to suffering—which is the doctrine of dependent origination (paṭicca samuppāda).

DeMoss develops the four noble truths along these lines, and has little more to say about the possibility that consequences carry over into another life. Neither he nor the authors cited by him appear to be aware of the late Buddhadāsa's view that we are reborn from moment to moment in this life—an interpretation historically similar to that of the Mādhyamikas, which has been described in detail by Donald Swearer (, 26–27).

On the whole Buddhists have less difficulty carrying over the consequences of this life into another than Hindus, who encounter more variety with regard to the modus operandi of rebirth, plus—as we have noted—a complex nomenclature for the terms used. But Hindus do possess the concept of a subtle body (liṅga‐śarīra), which, when conjoined with the ātman, identifies successive births (but at what stage—the embryo, the fetus, or what?). This subtle body, which is characterized by prakṛti (nature), contains accumulating karma and memory traces that carry over into another life—with or without a pause—which enable it to identify an appropriate birth.

Attempts have been made to detect evidence of memories between present lives and previous ones, but the Hindu theory of reincarnation as a whole does not stand or fall on the basis of such experiments since it can always be argued that memories of previous lives are suppressed. Belief in rebirth may influence an individual's world picture and shape his or her behavior along lines similar to those of believers in the four noble truths, but not a great deal else can be argued with certainty from a Hindu perspective. Some scholars have tried, but more work needs to be done before progress can be achieved in this field (Dayal ).