Over the years, numerous attempts have been made to find parallels between western and eastern thought. Fritjof Capra, for example, has noted the striking similarities between the discoveries of 20th century physics and those of eastern mystics. Some psychologists have also studied eastern theories of perception, memory, and self. Of course, these attempts haven't always been successful. At times, the differences are so fundamental as to be irreconcilable.
Western belief in the self pre-dates even Christianity. Plato, for example, argued for the self as a kind of ghostly occupant of the body, one that perhaps survived death. Aristotle disagreed, though he also attempted to define the self and never doubted such a thing existed (for him it ceased with the death of the body). Medieval Christians may have preferred the word 'soul,' but they still believed in some invisible essence that would be judged after death.
The modern western understanding of the self, however, really begins with Rene Descartes. Descartes, a 17th century French philosopher, argued that thought was the essence of a human being. When all was reduced down to basics, two kinds of 'stuff' remained: 'res extensa' and 'res cogitans.' The first meant roughly what a modern scientist means by the word 'matter.' The second translates as "thinking substance." The British philosopher Gilbert Ryle nicknamed this theory the 'ghost in the machine.'
Buddhism began with the Buddha's rejection of the Brahmannical tradition of ancient India. The Brahmans had believed in an unchanging self, something they named 'Atman.' The Buddha argued that this was an illusion and sought to replace it with 'anatman,' or 'no-self.'
Of course, Buddhist arguments against an enduring self are more subtle and complex than this. For a start, Buddhists argue that all entities, not just human beings, lack an enduring self. Indeed, there isn't even an Absolute or God. For many westerners, 'God' is a sort of 'Great Self' or magnified ego. In Buddhism, by contrast, ultimate reality is described as 'sunyata,' often translated as 'Emptiness.' But this Emptiness should not be confused with a nihilistic void. In Buddhist philosophy, Emptiness is more like a cosmic womb out of which everything arises and into which it returns.
Jung agreed that our understanding of the self is often flawed. Too often, people confuse the psyche with the ego. But the true self includes the whole of the psyche, both conscious and unconscious; the ego is the centre of consciousness alone and can never know the unconscious. In other words, the ego is a limited self that can never know the unconscious. So even though the true self is always there, it can never be fully known. When people say that someone is "highly self-aware," they really mean aware of their ego, not of the entire psyche.
For Jungians, there are two levels to the unconscious: the personal and the collective. The personal unconscious consists of repressed guilt, memories, desires, fears and so on. It is formed through personal experience. The collective unconscious, by contrast, is inherited. It is common to all human beings and contains what Jung called the archetypes. To the ego, it is perceived and experienced as something external.
Buddhists view things quite differently. In Zen Buddhism, for example, the self (or knower) and the known are one. The student may not grasp this, but hopefully, under the guidance of a master, he will experience 'satori', or sudden illumination, in which the truth of it is experienced rather than believed. Zen is full of playful paradoxes, the sort that drive western scientists mad. For a Zen practitioner, to grasp the true self you must first grasp that there is no self. Translated into Jungian terminology, you must grasp that both the conscious ego and the greater self, the total personality, conscious and unconscious, are insubstantial and illusory.
For a Buddhist, suffering is the result of illusion. People identify themselves with a narrow, fragile, time-bound self, one forever seeking to preserve and enhance itself. Seeing through this self is the first step. Zen Buddhists seek to replace the ego with what is sometimes translated as 'No-mind.' Unlike the Jungian unconscious, however, this is not an extra layer to the psyche but the original, true mind. Awakening to this is the only authentic cure for suffering.
Jungians also seek to increase consciousness and help the patient free himself from too narrow and exclusive an identity with his ego. But they do not seek to obliterate the ego altogether. A Jungian analyst helps the patient to understand why he is behaving as he is, to step back and see the greater meaning rather than allowing his frightened, grasping little ego to sweep him along. In his discussion with professor Hisamatsu of Kyoto University, an expert on Buddhism, Jung agreed that his system also aimed to free the individual from the ego. The ego tends to be caught up either in the world of things or to be, in Jung's words, "dragged along by the unconscious."
Buddhists often accuse western therapists of keeping the whole vicious cycle going. A patient comes to therapy with depression because he feels he has not achieved the things his parents expected of him. He is oppressed by a deep, unconscious sense of guilt, and so on. The therapist talks him through this and shows him that his superego is too demanding, that he needs to be kinder to himself and stop attempting to please the internalised image of his parents. A Buddhist would say the therapist is merely reinforcing the ego. The patient is still full of greed, ambition, fear and so on. Eventually he will return with a whole new set of problems. The key is to end his identity with the ego altogether.
There is common ground though. Both the Buddhist and the Jungian see the ego as relative rather than absolute. To a Buddhist it is an illusion, albeit a useful one. For a Jungian it is also illusory. People believe the ego is the centre of their psyche when in fact it is anything but. Someone who wished to follow both systems might see Jungian psychology as the first step. A Jungian therapist will help you see the relative position of the ego and recognize that it is a puppet of the unconscious. The Buddhist would then take you further, helping you free yourself from the unconscious and break through to pure 'No-mind.'