ABSTRACT
When, with Boole, alternatives (A, B) are considered as mutually exclusive, logical addition may be described as the process of taking A and B or A or B. It is a great and rare convenience to have two terms for denoting the same thing: commonly, people denote several things by the same term, and only the Germans have the privilege of referring to, say, continuity as Stetigkeit or Kontinuierlichkeit. But Jevons 1 quoted Milton, Shakespeare, and Darwin to prove that alternatives are not exclusive, and so attained first to recognized views by arguments which were plainly irrelevant.
