  General relativity in three spacetime dimensions is used to explore three
approaches to the ``problem of time'' in quantum gravity: the internal
Schr\"odinger approach with mean extrinsic curvature as a time variable, the
Wheeler-DeWitt equation, and covariant canonical quantization with ``evolving
constants of motion.'' (To appear in {\em Proc.\ of the Lanczos Centenary
Conference}, Raleigh, NC, December 1993.)
