Analysis of the Concept of Inertia and its Relation to Avicenna's "Mail" Theory from the Context of the Definition of Motion

From the analysis of the concept of inertia, two meanings can be deduced. The first one, that is, the body's resistance to change of state is accepted by all, but the second, that is, the perseverance of body in the state of rest or uniformly straight-line motion (Newton's first law), depends on what our definition of motion and rest is. If we accept the Cartesian definition of them, that is, they mean status, the latter meaning is acceptable, but it is not consistent with the Aristotelian definition. Avicenna proposed the theory of "mail" (Inclination/ Tendency) several centuries ago; resistant mail includes the first meaning of inertia, and the motive mail, although similar to the second one, he could not accept it because he rejects the Cartesian definition of motion. Avicenna's opinion is similar to Leibniz's, and he believes that the existence of the motive mail is necessary for the continuation of the motion. The aim of this research, as an example, is to provide attention to the high capacity of the opinions of Islamic philosophers such as Avicenna in the development of physical concepts and theories.