The question of whether or not there exists a continuity of consciousness after death has been an important aspect of philosophical reflection and debate from ancient Indian times to the present. When considering these matters from a Buddhist point of view, however, we have to bear in mind that the understanding of the nature of continuity of consciousness and the understanding of the nature of the ‘I’ or ‘self’ are closely interlinked. Therefore, let us first look at what it is that can be said to constitute a person.

According to Buddhist classical literature, a person can be seen as possessing five interrelated aggregates, technically known as the five psycho-physical aggregates.a These are the aggregate of consciousness, the aggregate of form (which includes our physical body and senses), the aggregate of feeling, the aggregate of discrimination, and the aggregate of motivational tendencies. That is to say, there is our body, the physical world and our five senses, and there are the various processes of mental activity, our motivational tendencies, our labelling of and discrimination between objects, our feelings, and the underlying awareness or consciousness.

Among the ancient schools of thought, which accepted the notion of continuity of consciousness, there were several non-Buddhist philosophical schools which regarded the entity, the ‘I’ or ‘self’, which migrated from existence to existence as being unitary and permanent. They also suggested that this ‘self’ was autonomous in its relationship to the psycho-physical components that constitute a person. In other words they believed or posited that there is an essence or ‘soul’ of the person, which exists independently from the body and the mind of the person.

However, Buddhist philosophy does not accept the existence of such an independent, autonomous entity. In the Buddhist view, the self or the person is understood in terms of a dynamic interdependent relationship of both mental and physical attributes, that is to say the psycho-physical components which constitute a person. In other words our sense of self can, upon examination, be seen as a complex flow of mental and physical events, clustered in clearly identifiable patterns, including our physical features, instincts, emotions, and attitudes, etc., continuing through time. Further, according to Prāsaṅgika-Madhyamaka philosophy, which has become the prevailing philosophical view of Tibetan Buddhism today, this sense of self is simply a mental construct, a mere label given to this cluster of dependently arising mental and physical events in dependence on their continuity.

Now, when we look at this interdependence of mental and physical constituents from the perspective of Highest Yoga Tantra,b there are two concepts of a person. One is the temporary person or self, that is as we exist at the moment, and this is labelled on the basis of our coarse or gross physical body and conditioned mind, and, at the same time, there is a subtle person or self which is designated in dependence on the subtle body and subtle mind. This subtle body and subtle mind are seen as a single entity that has two facets. The aspect which has the quality of awareness, which can reflect and has the power of cognition, is the subtle mind. Simultaneously, there is its energy, the force that activates the mind towards its object - this is the subtle body or subtle wind. These two inextricably conjoined qualities are regarded, in Highest Yoga Tantra, as the ultimate nature of a person and are identified as buddha nature, the essential or actual nature of mind.

Now, before we look more closely at the nature of the subtle body and mind, let us look at how the gross body and mind are thought to originate. The notion of dependent origination lies at the very heart of Buddhist philosophy. The principle of dependent origination asserts that nothing exists in its own right independent of other factors. Things and events come into being only in dependence on the aggregation of multiple causes and conditions. The process through which the external world and the sentient beings within it revolve in a cycle of existence propelled by karmic propensities and their interaction with misapprehension, attraction and aversion and conditions is described in terms of twelve interdependent links. Each cycle of the process begins with a misapprehension of the nature of actual reality. This fundamental ignorance acts as a condition for the arising of the propensities created by our past actions, mental, verbal and physical, which condition our dualising consciousness. Our dualising consciousness, in turn, conditions the qualities and mode of interaction of our psycho-physical aggregates, which condition our sensory fields, which generate contact, which generates sensations, and then in turn attachment, grasping, and maturation towards rebirth. At this point there is an interaction with the genetic constituents of the parents and subsequent interaction with the environment, and then finally we have birth, ageing and death. This cycle can be viewed as both illustrating the underlying processes of life, death and rebirth and as an illustration of the processes to be transformed on the path to liberation from suffering in cyclic existence.

The notion that there is a connection between this life and the events of both our previous existence and our future existence, follows from the Buddhist understanding of the natural law of cause and effect. For example, although we can speak of yesterday’s weather and today’s weather as distinct, today’s weather is inextricably linked with the weather patterns of yesterday. Even at the bodily level, in the case of our physical health for example, we know that events in the past affect the present and those of the present the future. Similarly, in the realm of consciousness the Buddhist view is that there is also this same causal continuum between the events of the past, present and future.

The Buddhist understanding of the continuity of personal experience, including our memories, can also be considered here. The Buddhist view is that the continuity of personal experience is primarily founded on the capacity for retention, which can be further developed during one’s meditative practice in this life. However, generally speaking, it is thought that if a person dies after a prolonged period of illness that has led to a prolonged degeneration of both physical and mental capacities, there will be a greater chance of many of the personal characteristics, including memories etc., being lost. On the other hand, in the case of someone who dies a sudden death, when the mind-body relationship at the gross level is still very firm, it is thought that there is a greater chance of carrying forward the acquired characteristics and memories, etc. Nonetheless, in both cases, the characteristics carried forward from a previous life are generally thought to be most strongly felt at an early stage of one’s rebirth. This is because the personal characteristics of the previous life are thought, generally speaking, to be quickly overwhelmed by the developing characteristics inherited from the parents of the present life. Nonetheless, as I have mentioned, much depends in this respect on the individual’s capacity for recall and this capacity for recall is dependent on a deepened retentive training acquired in this lifetime.

Now, let us look at the possible states of existence one can be born into. From the Buddhist perspective, rebirth in conditioned existence can take place in one of three realms: the formless realm, the form realm or the desire realm. The form and formless realms are fruits of subtle states of consciousness, attained upon the realisation of certain meditative concentrations. Our realm, the desire realm, is the most gross of these three. Six classes of beings are described as inhabiting the desire realm: gods (mundane celestial beings whose primary mental state is exaltation), antigods (who are predominantly hostile and jealous), human beings (who are influenced by all the five dissonant mental states), animals (who are under the sway of delusion), anguished spirits (who are under the sway of attachment and unsatisfied craving) and hell beings (who are overwhelmed by hatred, anger and fear). In the literature of Highest Yoga Tantra, the evolution of all the three realms of conditioned existence are described in terms of differing expressions or states of energy and, as I have mentioned, it is said that our fundamental ignorance is the root of conditioned existence and that karmic energy is its activating force. In the Buddhist view, therefore, it is the nature of our habitual tendencies that generates our future existence, driven by the natural law of cause and effect.

Further, when we observe the patterns of arising and subsiding that underlie the dynamic nature of the physical environment, the cycle of days and nights and the passing of the seasons, for example, and we observe how matter arises from insubstantial subatomic particles and we look at the patterns of causal connectedness in the arising and dissolution of our mental experiences from moment to moment, across the differing phases of deep sleep, dreams and our waking state, the notion of continuity of consciousness can come to be seen to be in accord with both the nature of our environment and the nature of our mental experience. Certainly, it has often been argued that one advantage of accepting the notion of continuity of consciousness is that it gives us a more profound ability to understand and to explain the nature of our existence and of the universe. In addition, this notion of continuity and causal interconnectedness reinforces a sense of consequences for our own actions, in terms of both the impact on ourselves and the impact on others and the environment.

So, in summary, when considering the notion of continuity of consciousness we must bear in mind that there are many different levels of greater or lesser subtlety in the states of consciousness. For example, we know of course that certain qualities of sensory perception are dependent on the physical constitution of the individual and that when the physical body dies, the states of consciousness associated with these sensory perceptions also cease. But, although we know that the human body serves as a condition for human consciousness, the question still remains: what is the nature of the underlying factor or essence that accounts for our experience of consciousness as having the natural quality of luminosity and awareness?

Finally, then, when considering the interrelationship between mind, body and the environment at the subtle level, we know that material things are composed of cells, atoms and particles and that consciousness is composed of moments. That is to say that mind and matter have distinctly different natures and therefore have different substantial causes. Material things come into being based on other material entities such as particles, atoms and cells and the mind comes into being based on a previous moment of mind, which is something that is luminous and has the capacity to be aware. Each moment of awareness therefore depends on a previous moment of awareness as its cause. This is the reasoning upon which Buddhist logic asserts that there is at the level of subtle mind and subtle wind a beginningless continuum of mind and matter.

It is through reflection on the above themes: the law of cause and effect, dependent origination, the dynamics of our physical environment, and, based on our analysis of the nature of mind, the mode of the arising and subsiding of thoughts, the shifts in the modalities of our consciousness between deep sleep, dreams and our waking state, etc., that the notion of continuity of consciousness may first become established as relevant to the understanding of our current condition. Once the notion of this continuity has been confirmed, through reflection and experience, then it becomes logical to prepare oneself for death and for future existences.

Now, as to the nature of the actual preparation itself, this will depend on each individual’s depth of spiritual aspiration. For example, if an individual is simply seeking a favourable rebirth as a human being, there is no need to engage in a sophisticated meditative path related to the processes of death and rebirth. Simply to live a virtuous life is seen as sufficient. Similarly, in the case of those who are seeking personal liberation from conditioned existence and also in the case of those whose practice is confined to the sūtra level of the Mahāyāna path, their meditative preparation will be limited to ensuring the attainment of successive forms of existence that will be conducive to the continuation of their journey towards enlightenment. For these three kinds of individuals, no actual techniques for utilising the time of death as an essential element of the spiritual path have been set down in the classical Buddhist literature. Nevertheless, since the understanding of the processes of death, the intermediate state and rebirth are crucial to our understanding of the nature of existence, we do find extensive discussion of these three processes, even in the texts which relate to the aspirations of these three kinds of persons.

It is exclusively in tantra, however, and particularly in Highest Yoga Tantra, that the methods for utilising the processes of death, the intermediate state and rebirth are specifically taught as the basis for achieving liberation from cyclic existence. These methods involve the development of a skilful relationship with certain experiential stages that an individual actually induces with the intention of enhancing spiritual realisation and the fruition of their capacities as a human being.

Generally speaking, the practices of Highest Yoga Tantra present a spiritual path which enables the individual to attain complete buddhahood within a single lifetime, prior to the moment of death. Yet, for those who are unable to achieve this, it becomes crucial to use the transformative opportunities offered by the naturally occurring processes of death, the intermediate state and rebirth. Hence, in Highest Yoga Tantra, it is not merely the preparation for a more developed future rebirth which is important, but of more fundamental significance is the personal preparation for using one’s own death and subsequent states as a means of achieving liberation.

In the literature of Highest Yoga Tantra, as I have mentioned, the three realms of conditioned existence into which a human being may be born are described in terms of differing expressions or modalities of energy (rlung) and it is said that our fundamental ignorance is the root of conditioned existence and that karmic energy is its activating force. Further, from the tantric perspective, death, the intermediate state and rebirth are also seen as nothing other than differing modalities of karmic energy. The point at which the gross levels of energy are completely dissolved and only the subtle energies remain is death. The stage at which these energies unfold into a more manifest form is the intermediate state, and the stage at which they eventually manifest substantially is called rebirth. Thus, all three states are differing manifestations of energy (rlung). Based on this understanding, since death is the state when all the gross levels of energy and consciousness have been dissolved, and only the subtle energies and consciousnesses remain, it is possible for an advanced yogin to meditatively induce a state which is almost identical to the actual experience of death. This can be achieved because it is possible to meditatively bring about the dissolution of the gross levels of energy and consciousness. When such a task is accomplished, the meditator gains an enormous potential to progress definitively in his or her spiritual practice. For at the stage, when the experience of fundamental inner radiance is genuinely effected through such a method, the yogin gains the capacity to actualise the illusory body of the meditational deity - thus ensuring the realisation of perfect buddhahood in this lifetime.

This achievement of perfect buddhahood entails the actualisation of the three dimensions or bodies of a buddha (trikāya). These fruitional bodies are related both to our ultimate natural state and to the emanational qualities of full enlightenment. Interestingly, we see exactly the same pattern of dimensions in our ordinary existence. Death is the point at which both the physical and mental fields dissolve into inner radiance and where both consciousness and energy exist at their most subtle non-dual level, as in deep sleep. This mode in its fruitional state is the Buddha-body of Reality (dharmakāya). Then, from within this essential or natural state, one enters into the intermediate state, where, although there is perceptual experience, the phenomenal forms are comparatively subtle and non-substantive, as in a dream. This mode in its fruitional state is the Buddha-body of Perfect Resource (sambhogakāya). Then, from this state, one assumes a grosser physical existence culminating in actual rebirth, as in our normal waking experience. This mode in its fruitional state is the Buddha-body of Emanation (nirmāṇakāya). Thus, we see a direct parallel between the three natural states of our existence and the three dimensions of a fully enlightened being.