„A proposition being a portion of discourse in which something is affirmed or denied of something, the first division of propositions is into affirmative and negative. An affirmative proposition is that in which the predicate is affirmed of the subject; as, Cæsar is dead. A negative proposition is that in which the predicate is denied of the subject; as, Cæsar is not dead. The copula, in this last species of proposition, consists of the words is not, which are the sign of negation; is being the sign of affirmation.“ (Chap. IV, § 2) #Mill #proposition