ABSTRACT
If it is true that “all barristers are lawyers”, then it is true that” some lawyers are barristers”, and it is false that “some barristers are not lawyers”. This exemplifies the kinds of relation in which propositions can stand to each other, such that if one proposition is true, certain others are true and certain others are false. We habitually make statements dependent for their cogency on the existence of such definite relations between propositions, but we seldom pay attention to those relations as such, and may even be slightly surprised to discover that they exist at all. Those relations are now to be systematically examined, the different kinds being distinguished and their characteristics noted.
