  Kant also asserts that the very possibility of natural science proper depends on the law of inertia, since the rejection of it would be hylozoism, “the death of all natural philosophy” (4:544). In a later remark in the Mechanics, Kant explicitly objects that “the terminology of inertial force (vis inertiae) must be entirely banished from natural science, not only because it carries with it a contradiction in terms, nor even because the law of inertia (lifelessness) might thereby be easily confused with the law of reaction in every communicated motion, but primarily because the mistaken idea of those who are not properly acquainted with the mechanical laws is thereby maintained and even strengthened” (4:550). Kant goes on to point out that if inertia were to entail an active force of resistance, then it would be possible that when one moving body hits another, the moving body has to apply part of its motion solely to overcome the inertia of the one at rest and might not have any motion left over, as it were, to set the body at rest into motion, which is contrary to experience (and Proposition 2).