On force and the inertial frame, Robert W. Brehme, Am. J. Phys. 53(10), October 1985
The logical difficulty surrounding the definition of an inertial frame and Newton's first law of motion can be circumvented by defining the inertial frame in terms of its spatial and temporal properties properties, as embodied in the special theory of relativity. Whether or not these properties apply can be determined, in principle, by experiment. The mass of a body is measured through a completely inelastic collision with a body whose mass is taken as the standard. Rather than attempt to define force by a means not involving Newton's second law, we use the second law as the definition.