  In modern physics, a profound thought is "symmetry inducing interaction". In
this paper, following this though, we pointed out that a symmetry of the
quantum state of the vacuum (the so-called "intrinsic symmetry") rather than
the usual symmetry of the Lagrangian or the action that plays the key role to
construct a correct theory for quantum gravity. Based on a hypotheses about the
intrinsic symmetry of the spacetime, we developed the theory for quantum
gravity and found that the gravitational interaction naturally emerges.
