AbstractFollowing Einstein, we consider a simple model of a star, namely a spherically symmetric distribution of particles which are all moving along circular orbits around the center of the particle cluster. According to arguments given by Einstein, Laue, Treder and others, the existence of stationary circular motions for all values ofrcan be considered as a necessary condition for all collapse‐free relativistic (classical) theory o gravitation. The discussion shows that, assuming the validity of the weak principle of equivalence and the principle of causality, one has to consider theories with ag00‐function different from the Einstein‐Schwarzschild one. We discuss someg00types and show that our point of view leads in the direction of gravitational equations with a cut‐off