The Dynamics of Aristotle

Abstract

Kinematics is necessarily followed by dynamics, i.e. the problem of motion under the action of forces. The laws of dynamics (also called the laws of motion) must be formulated. The first such laws were formulated by Aristotle. It is even possible, by studying his texts, to reconstruct his two laws of dynamics. The first says that a body, acted upon by no force, remains in the state of absolute rest, and the second states that a force is necessary to move the body, i.e. to change its state of rest into motion. The first law, just as in Newtonian mechanics, establishes the “standard of motion” (in this case the state of absolute rest); the second determines the action of a force as causing a deviation from this standard. Aristotle’s laws in this chapter are reconstructed in close analogy to Newton’s laws and by ascribing to Aristotle some Newtonian concepts, but, in fact, there is a long evolution of concepts that separates Aristotle from Newton. This is the principal reason why our reconstruction of Aristotle’s dynamics is only a strong stylization of his rather fuzzy ideas.