Experience is the view, so to speak, within a cognitive domain, from the perspective of the subject. This viewpoint is literally a dimensionless point, interior to experience and at its center. The pure subject is nothing other than this point. It is therefore not an object of any sort, nor any element of the panorama of experience. Subject and object are totally disjunct. The object is seen; the subject is seer. While in truth the subject never experiences itself, yet it may come to mistake some portion of its experience of the world for itself.
In subjective consciousness there is a shift, so that the cognitive domain is no longer naively interpreted as the world, but is seen as an inner view of the workings of the cognitive system. The subjectively conscious mind recognizes all experience to be a product of both world and self. But this "self" is implicitly the cognitive system-- part of the organism. It is not the pure subject, which remains interior to all objects of consciousness, the center of all experience whether of self or of world. Identifying the subjective content of experience as oneself is an important evolutionary step. But from an absolute point of view no content of experience is the self as pure subject.
As motor agent, the subject is not the body which performs actions, nor the thoughts or feelings which animate them. As experiential witness, it is not the brain nor any entity such as the soul. And since it is a dimensionless point, there is nothing but location in space and time to distinguish one subject from another, except through the intentional act of identification with a particular cognitive system. Therefore, in an absolute sense there is not a plurality of subjects, but qualitatively merely one. There is but one agent and one witness, manifest in all the apparently separate forms of individual organisms. This truth, of the unity of subjects, runs parallel to the unity of the cosmos as one undivided object or process.
What is the role of this subject in the behavior of a cognitive system? Strictly speaking the subject remains an uninvolved witness. It does not enter into decision making except the meta-decisions of whether to allow the machinery of decision making to proceed, whether to identify, whether to pay attention, etc. Its decisions concern the relationship to experience rather than to its specific contents. To identify is to abdicate the responsibility of the witness to monitor the cognitive process. We have described identification as adopting the viewpoint of a playing piece within a game. The player as subject is always free to take the game seriously or not. The player is the subject in its role as free agent, as distinguished from observer. The subject as player remains unidentified with its actions, just as the subject as cognitive witness is unidentified with its perceptions. In the game, indeed, actions are not the player's but those of the game itself! The free player embraces the game as a format for play, but not to the extent of forgetting its own freedom, nor that the game is only a game. At this level, all limitation is a voluntary acceptance of the world of the game.
By definition, the subject stands always on the opposite side, of the arrow (or lens) of mind, from objects. The subject is not any object of consciousness, but is consciousness itself. Not itself a thing, it is a point of view, never what is seen from that point of view. We could think it is a person or agent pointing, but this begins to make the subject an object of thought, even a body, which it is not. Since awareness can always point to any pointer, the subject is always interior to what can be pointed to.
The arrow of awareness points through the lens of mind, which has its own focussing and distorting properties and is normally perceived as transparent-- that is, not perceived at all. It is possible to look at the lens of mind-- for it to be an object of awareness or thought-- provided we understand that what we think we are seeing as the lens is itself a product of the lens, a mere image. In other words, the lens can be known only through inference from its distorting effects upon experience. It is better regarded as a theoretical construct rather than a literal object of perception. (We are speaking not of the brain, which is a physical object, but of the mind, which is not). An analogy might be the black hole which acts as a gravitational lens. It cannot itself be seen, but produces visible effects on the background of more distant objects whose images are distorted or multiply refracted around it.
True subjectivity follows from the thought "I am". This is totally disjunct and complementary to the objectivity of natural science, which follows from the thought "the world is". One is about the object-- even objects of thought-- while the other is about the point of view that is aware of objects. The difference is like that between noun and preposition. We confuse the issue by conceiving them on the same footing-- as both words-- but what the words point to are totally unalike. The subject cannot know itself, when knowing is an activity applied to objects.
From a scientific and also commonsense point of view, information and causal forces in the physical world impinge upon the organism, a physical object, driving its responses. But from an existential point of view, awareness goes out from the subject, through the organizing lens of mind, which imbues the objects of consciousness with its qualities. The body can be described causally, but the ultimately the subject cannot be described at all, since it is not a thing like the body, an objet trouve, but realizes itself through intentional acts of transcendence. The self is not an entity (e.g. a "soul" or "spirit"), and therefore not individual or plural. It is not real in the passive sense that physical things (like the brain) are real. We may inquire how the brain arose, and the behavior of the organism, but not how mind arose, which is self-creating outside time. Its system of entailments are logical rather than causal.
There is a tendency to imagine mind as a subtle physical substance-- a "subtle body". Since the physical world is the natural object of mind, when the mind is its own object of thought, it treats its contents as elements of a quasi-physical domain. Its operations, which are syntactic, are considered to have semantic content, to refer to the world-- and therefore appear tinged with substance. Though a system of logical entailments, they are modeled by causal processes within the brain. But all this is irrelevant to the status of mind: logical entailment constitutes a separate realm from the world of cause. It is not an ersatz physical world, any more than a preposition is an imitation noun. Because its natural object is the world, mind conceives all as thing; but its own nature is different.
To resolve the Mind-Body Problem ontologically is already subtly to adopt a realist or materialist stance, because it insists on speaking of what exists, while the model for existence implicitly remains physical . Perhaps the more important question concerns our relationship to what exists. Idealism then becomes not an ontological posture-- not simply a statement that "the self or mind alone exists"-- but more a proclamation of responsibility for one's experience. Realism is then not a denial of subjectivity, but a deeper understanding of the subject-object relationship.