  (3) In addition to the (relatively) basic powers of natural inertia  and solidity, Leibniz recognizes two further derived passive powers  of bodies. The first, which we might call “firmness” or  “cohesiveness,” concerns the ability of a body to resist  being scattered or torn into pieces. (An egg and a baseball differ  not only with respect to their “natural inertia” and  impenetrability, but also with respect to their ability to hold  themselves together, as it were, under impact.) In the New  Essays, Leibniz writes: