A proposal is made for a new discipline, ecological mechanics. This version of mechanics is complementary but not reducible to classical relativity, and quantum mechanics. Where traditional mechanics attempt causal analyses for all motions, ecological mechanics explicitly addresses the motions of living systems that exhibit goal-directedness. The shortcomings of the physical geometries underlying traditional mechanics are reviewed, and means are proposed for redressing their deficiencies for modeling the behaviors of intentional systems. This demands a new physical geometry that retains all the best features of the old ones but is extended to accommodate intentional acts. The new physical geometry combines a variant of Minkowski's space-time geometry with a (Cantorian) fractal geometry which reformulates Einstein's energy conversion law ( E = mc 2) and Planck's energy distribution law ( E = fh) so that they apply, more realistically, to the scale of living systems. A new scaling technique called ecometrics, is introduced for accomplishing this feat. This approach assumes a symmetry operator which acts to ‘intentionalize’ causation and to ‘causalize’ intention so that perceptual information and action control processes are defined over a commensurate but dual measurement bases. The promise of ecological mechanics rests on the imputed discovery of a new conservation law which holds locally rather than absolutely. Empirical evidence is reviewed and graphically portrayed mathematical arguments are given that tend to support the hypothesis.