This chapter explains the meaning of the partition of Greek mechanics into Aristotelian and Archimedean. In the first part the Aristotelian mechanics is considered that identifies as a principle the following VWL based on virtual velocity: The effectiveness of a weight on a scale or a lever is the greater the greater its virtual Velocity. In the central part the Archimedean mechanics is considered where there is no reference to any VWL. In the final part devoted to the late Hellenistic mechanics, the VWL of Hero of Alexandria is considered for which the possibility of raising a weight is determined by the ratio of its virtual displacement and that of the power. The law is presented not as a principle but as a simple corollary of equilibrium.