As the famous story goes, following a profound experience at the age of 35, Siddhartha Gautama professed to have penetrated through his ignorance and confusion to uproot the conditions of cyclic existence before proceeding to instruct those who followed him to do the same. As is also well known, he didn't write anything down. His teachings were 'preserved' orally for around 300 years before being committed to the written word. Despite the occasional claims of putative anthological eminence the sheer proliferation of 'Buddhist' texts makes any knowledge of what the Buddha taught a question of choosing a favoured school and interpretation*.
I choose the school of Mādhyamika, and more specifically, Mādhyamika as interpreted by Garfield and Magliola. One important reason for this is that it is evident from sections of the Pali canon** that Siddhartha Gautama believed in karma as the process of rebirth, as was the dominant belief during his time. Indeed most biographies state that it was the experience of 'seeing' his previous lives and how they conditioned his present one that was the first of three insights leading to his enlightenment. For reasons stated above, just what the Buddha understood by 'rebirth' and how it differed from the prevailing world-view at the time is far from conclusive and would be an interesting topic to investigate - one which I may need to return to. However, like the majority of the Western world, I don't believe in rebirth in any literal sense and so my present concern is how Buddhism - in particular dependent origination and how it relates to samsāra and nirvāna - can be interpreted in the absence of what many consider to be the fundamental concept of rebirth. I believe Garfield's interpretation of Mādhyamikan Buddhism provides a good account of how this is possible.
He does this by distinguishing the psychological/philosophical aspects of Buddhism from the cosmological and soteriological aspects which may or may not have been directly inherited from the Vedic tradition. Transmigration (rebirth) is discussed when focussing on Chapter XXVI of the Mūlamadhyamakakārikā - Examination of the Twelve Links.
One is caught in cyclic existence for a reason, Nāgārjuna asserts, because one acts. There are three general kinds of actions distinguished in Buddhist action theory - physical, verbal, and mental. These actions in turn have immediate psychological consequences for the agent. That is they give rise to new psychological dispositions. In the framework of Buddhist action theory, these dispositions are themselves conceived of as actions existing in a potential form, and of course when actualised, they emerge as new actions of body, speech, or mind. These in turn lead to a variety of new such consequences and to the continuation of cyclic existence. Transmigration - the continuation of samsāra - for Nāgārjuna is then simply a dependent consequence of one's actions.
Continuing through the traditional presentation of the twelve links, Nāgārjuna notes that consciousness is a consequence of dispositions and depends on them and that "name and form" follow as a consequence of consciousness. These, therefore, are obviously also dependent phenomena.
There are two ways to think of the twelve links, generating two parallel circles of explanation: One can approach them from the standpoint of transmigration, which provides a standard Buddhist explanation of the cycle of life. Or one can think of them as providing a phenomenological analysis of the nature of experience. In the former sense, we could say at this point in the story that actions performed in the past and dispositions inherited from one's previous history lead to new actions whose consequences are cyclic existence. In particular, the actions and dispositions from one's prior life, on this view, lead to the generation of a new consciousness, which upon entering the womb, gives rise to a body that will get a particular name.
Or, from a phenomenological perspective, we can see dispositions to attend to or to interpret particular phenomena in certain ways (perceptual or conceptual "sets") and actions upon them leading to our becoming aware of external or internal phenomena (consciousness), which leads to our representing them as having determinate locations and denominations (name and form). These two levels of analysis are obviously quite compatible, and while the former plays a central role in Buddhist cosmological and soteriological theory, the latter is important in Buddhist psychology and practice.
(Garfield, The Fundamental Wisdom of the Middle Way, p336-337)
It is the latter understanding of the twelve links which I believe survives the transition to the contemporary Western world without much difficulty. I further believe that the Buddhist analysis of experience bears a strong resemblance to the contemporary study of what is termed psychological essentialism although I have only just started my reading on the subject. This is what I want to explore in more detail now.
* I should qualify this statement here and acknowledge that Zen Buddhism claims to be a "teaching beyond scriptures" and insists that what the Buddha taught can only be understood through direct experience.
** For example, in the Pali canon there are detailed descriptions of the six realms of rebirth, our human world being the most opportune for the achievement of nirvāna.