Some soldiers are cowards. Some subatomic particles are not electrons. The significance of this will be discussed in greater detail, when we study predicate logic. If a statement affirms that one class is wholly or partially included in another class, then the quality is affirmative . If the statement denies that one class is wholly or partly included in another class, then the quality is negative .
Universal statements refer to all members of the class denoted by the subject term.
Particular statements refer to only some members of the class denoted by the subject term. There is a method that we will study in the next section that will allow us to test their validity. And validity is one of the trademarks of a good argument. But there are also some complications. Categorical statements must be expressed in the standard forms depicted above.