This is the Center, or hub, of the Wheel around which all states of consciousness revolve. In the language of the Wheel this is AWARENESS, a transcendental state which is fundamentally different than consciousness.
Symbolized by the Sun, Awareness is not really an impulse or part of speech. It is the silence of the listener which allows for understanding of another's speech. It is a dynamic state of Nothingness.
The Sun symbolizes the Awareness - the shining radiance - behind all of the other impulses, the essence behind and linking the different personalities. It stands for the Higher Self beyond the Ego, a state of higher consciousness, of light. The pure Awareness pulls together and integrates all of the diverse aspects of our Self into a cohesive whole. We first become aware of the Higher Self in peak experiences, and then eventually by mastery of all of the other impulses, we start to live in the light, and a higher pattern emerges.
The center of the Wheel is outside of time, outside of history. It is the Alpha and Omega point of the beginning and end of the Universe. This trans-temporal place provides the connections between all historical Ages, the link between all cultures. In a spatial sense it represents both the center of the Earth, and the center of the Universe, the place of the Big Bang from which All That Is arose.
The center is the core of Being. It is the Nothing which holds everything together. It is the black of the Mandelbrot set, the Zero connectivity to all iterations. This is the place in each person where Wisdom is nourished and grows.