Глава LXIII. О суждении, утверждении и отрицании

It should be noted that both an affirmation and a negation are called a judgment. A statement shows what belongs to some object, i.e. what an object is: for example, Socrates is wise, Socrates is walking. Negation, on the contrary, shows that it does not belong to any object, i.e. what an object is not: for example, such and such is not wise, such and such does not take a stroll. Every statement has its opposite negation, and every negation has its opposite statement. A negation that is the opposite of an affirmation and a statement that is the opposite of a negation is called a contradiction. One of them is necessarily false, and the other is necessarily true. You might be interested in: