The present paper develops arguments for the need to formulate the basic theories of physics in terms of a six-dimensional manifold, as opposed to the four-dimensional space-time continuum of conventional theory. Employing a purely classical approach, some of the dynamical consequences of such a formulation with regard to both electrodynamics and gravitation are evaluated. The results lead to interesting implications with regard to various questions such as the occurrence and importance of superluminal particles, the existence of two or more physically distinct time scales, and the variation of the gravitational coupling constant G and the law of energy conservation. The analysis also suggests a physical interpretation of the additional coordinates that occur in the metric.