In terms of psychological symbolism, it expresses the union of the personal temporal world of the ego with the non-personal, timeless world of the non-ego. The two interpenetrating triangles represent the wholeness of the psyche or Self, of which consciousness is just as much a part as the unconsciousness.
E a esfera, de bónus: The circle (or sphere) as a symbol of the Self. It expresses the totality of the psyche in all its aspects, including the relationship between man and the whole nature. The ultimate wholeness.
Man and its symbols, Aniela Jaffé