Newton’s law of universal gravitation underpins our understanding of the dynamics of the Solar
System and of a good portion of the observable universe. Generally, in the classroom or in
textbooks, the law is presented initially in a qualitative way and at some point during the
exposition its mathematical formulation is written on the blackboard and some quantitative
consequences are discussed. In the present paper we argue that this approach can be improved by the
use of plausibility arguments.