ABSTRACT
This chapter examines Gottfried Wilhelm Leibniz' definition of necessity with reference to certain objections or questions suggested not so much by philosophical controversies of Leibniz' own time as by critical discussion of problems relating directly or indirectly to the problem of necessity. There are two points to be noted in connection with the use of “necessary” in application to the principle of non-contradiction itself. In the first place, it is not clear that “necessary” in this use is susceptible of definition in non-modal terms. Secondly, the necessity involved appears to be only a relative necessity: the principle is necessary if there is to be significant discourse. Leibniz does, however, recognize the existence of negative necessary truths, and he attempts to fit them into his “identity” theory of necessity by introducing, in the Nouveaux Essais, the somewhat paradoxical expression “negative identities”.
