pp. 161-166:
What exactly is consciousness, and where does it come from? Did the ineffable phenomenon arise naturally through the processes of evolution, once brains became sufficiently complex? Or has consciousness coexisted with the material universe since beginningless time? Does the idea of a division between the mind and the body make any sense? If consciousness can exist apart from the body, does this perhaps explain accounts of reincarnation?
THUAN: Most biologists believe that in the process of evolution, consciousness arose when the networks of brain cells in living beings reached a treshold of complexity. This theory implies that consciousness emerged, just as life itself, from inanimate matter. Does Buddhism agree with this view?
MATTHIEU: Buddhism agrees with most opinions of science concerning the universe's evolution—except, of course for the notion of a "beginning"—but it disagrees about the origin of consciousness.
There is a fundamental quality of mind that is present at all times: the basic quality of knowing, of being aware. Without this cognitive quality, one cannot speak of a mind or a consciousness. It is the mere fact of knowing that differentiates a conscious phenomenon from an inconscious one, like a stone. In Buddhist terms, it is said that consciousness possesses a fundamental clarity of luminosity, opposite to the "cognitive darkness" of inanimate objects.
This basic awareness of consciousness is a primary phenomenon. Matter is usually considered to be a primary phenomenon, meaning that we can explain how matter works and transforms itself and analyze it in terms of particles or energy, but its existence is a given fact of the phenomenal world. In the same way, from an experiental perspective (the first-person experience), consciousness can be considered as a primary phenomenon. It is needed for the arising of any thought, remais as the basis of every thought that goes through the mind, and remains after a particular thought has vanished. It is the most fundamental aspect or nature of mind. pure consciousness knows itself, but not in a subject-object relationship. It is self-illuminating like the flame of a lamp that illuminates other objects, but does not need to illuminate itself, for light is its very nature.
We can investigate our fleeting thoughts and find various causes that triggered them. But as to consciousness itself, we can simply acknowledge its presence and understand that the present instant of consciousness has been triggered by a former instance of consciousness. We cannot, however, find introspectively a more fundamental cause to consciousness. We may study consciousness from many outer viewpoints, such as the study of the brain and of behavior, but we have to acknowledge that the primary nature of consciousness belongs to the realm of our experience, not to the third person's perspective.
Buddhism distinguishes three levels of consciousness: gross, subtle, and extremely subtle. The first one of these is the level of the biochemical workings of the brain. The second is the subjective experience that we customarily call conscience, that is to say the mind's faculty to, among other things, examine itself, to ponder over its own nature and exercise freedom of choice. The third level, that of the extremely subtle, which is the most important is also called "the fundamental luminosity of the mind." This is a state of pure awareness that transcends the perception of a subject/object duality in the world and breaks free from the constraints and traps of discursive thought.
These three types are not separate streams of consciousness, but lie at different, increasingly deep levels. The gross and subtle levels both arise from the fundamental level, as opposed to the other way around, as might be expected. The brain, and in fact the whole body, even extending outside the body to the environment, provide gross and subtle consciousness with the conditions that allow them to manifest themselves. These levels of consciousness are both shaped and modified by the brain and environment and can in turn modify the brain and the body. The activities of theselevels of consciousness are correlated to the brain, and they can't manifest themselves without a body.
Fundamental consciousness is quite different. In the tantras—Buddhism's profoundest vision—fundamental consciousness is called "pure awareness" (rigpa). This type of consciousness is always present behind the screen of thoughts. It allows the thought to arise but can be experienced in the absence of all mental constructs. It's also called "the primordial continuity of the mind", "natural luminosity", "the ultimate nature of the mind", "the natural state of consciousness", "essential simplicity", "primordial purity", and "spontaneous presence."
In normal life, only the gross and subtle levels of consciousness can be discerned, because the fundamental level has been cloacked by the veil of ignorance, just as the sun can be momentarily covered by clouds. however, ignorance can no more affect the primordial level of consciousness than clouds can affect the sun.
THUAN: But where do conscious phenomena come from? Do we need a "spark" to set alight life and consciousness in inanimate atoms?
MATTHIEU: This "spark" idea creates a major problem. According to this conception, consciousness had a beginning. If so, either it was created ex nihilo (without a cause, or by a creator—and we've already seen how Buddhism refutes these two ideas), or it gradually came to life in inanimate matter, as most biologists and physicists think. One of them, the physicist Brian Greene, wrote the following letter to me: "I think that consciousness is a reflection of microphysical processes (of great and stupendous speed and complexity). Although the qualitative features of consciousness differ dramatically from the properties of the physical constituents in which it is based. I do not think this points toward there being something 'else' than the physical structure."
Buddhism would answer that cause and effect must have a common nature when the cause is substantially responsible for the effect. (When the cause is simply a cooperative condition for the effect, as described below, the two may be quite dissimilar.) A moment of consciousness can only be caused by a preceding moment of consciousness. If something could be born from something utterly different, then anything could be born from anything else. Thus the fundamental level of consciousness cannot have arisen from inanimate matter, and it doesn't necessarily, always and in all contexts, depend on being embodied in a physical form.
The Dalai Lama explained this idea as follows:
It is clear that consciousness depends on the functioning of the brain, so there is a causal relationship between the brain function and the arising of gross consciousness. But there is a question I continue to consider: What type of causal relationship is it? In Buddhism, we speak of two types of causes. The first is a substantial cause, in which the stuff of the cause actually transforms into the stuff of the effect. The second is cooperative condition, in which one event takes place as a result of a preceding event, but there's no transformation of the former into the latter...Let's apply this to the causalorigination of consciousness and its relationship to brain function. What type of causality exists there? We have, experientally, two types of phenomena that seem to be qualitatively distinct: physical and mental phenomena. Physical phenomena seem to have a location in space and time, and they lend themselves to quantitative measurement as well as having other qualities. Mental phenomena, in contrast, do not evidently have a location in space, nor do they lend themselves to quantitative measurement, for they are of the nature of simple experience. It seems that we're dealing with two very different types of phenomena. In this case, if a physical phenomenon was to act as a substantial cause to a mental phenomenon, there would seem to be a certain lack of accord between the two.(Ref.)
THUAN: The materialistic, or "monist," position is that the brain is comprised of a mass of neurons, and that consciousness is simply the result of electric currents that run through the neuronal circuits. As the eighteenth-century doctor Pierre Cabanis expressed this idea, "the brain secretes thoughts as the liver secretes bile."
Neurobiologists argue that our brains, and in turn our minds, are constantly being shaped by our interactions with the world around us. Consciousness is born from this constant interaction (Ref.). The meaning of the world emerges from the permanent activity of our bodies in a particular environment. Neurobiologists also argue that consciousness emerges from inanimate matter that constitutes our brains. They see no need for an additional ingredient that transcends the physical.
When Buddhism conjectures that there is a level of consciousness that transcends the physical, isn't falling back into Descartes's mind-body dualism, in which there are two types of reality, that of the mind (or thought) and that of the material world? According to Descartes, the mind is pure consciousness, doesn't occupy space, and can't be subdivided. On the other hand, matter is unconscious, occupies space, and can be divided. Man has a double nature: we think, but we also have a material body.
MATTHIEU: Buddhism's conception is radically different from Cartesian dualism. We believe that there's merely a conventional difference between matter and consciousness because, in the end, neither of them has an inherent existence. Because Buddhism refutes the ultimate reality of phenomena, it also refutes the idea that consciousness is independent and exists inherently.
One of the arguments we use to convey this point depends on the ability to subtle consciousness to be aware of itself. We would argue that a truly existing consciousness could no more reflect on itself as an object than a sword could cut itself. The reasoning applies, however, only to the concept of consciousness as an intrinsically existing function. Considered as the continuum of a "cognitive function", consciousness can indeed know itself.
What we've called "fundamental luminosity" is a natural self-conscious quality that lies beyond subject-object duality. We thus escape from the infinite regress of another observer observing the observed. This fundamental level of consciousness and the world of apparent phenomena are linked by interdependence, and together they form our perceived world, the one we experience in our lives.
Descartes dualism, lacking as it does the concept of interdependence, is limited by an absurd notion of the strict wall between mind and matter. How can consciousness interface with the material world if both exist as such independent, inherently existing entities that have nothing in common?