Critique of the Wheeler-DeWitt equation

The Wheeler-DeWitt equation is based on the use of canonical quantization rules that may be inconsistent for constrained dynamical systems, such as Einstein’s gravitational field equations. The resulting quantum dynamics has no classical limit, and it suffers from the infamous “problem of time.” In this article, it is shown how a dynamical time (an internal “clock”) can be constructed by means of a Hamilton-Jacobi formalism, and then used for a consistent canonical quantization, with the correct classical limit.