Being Logical

A is a statement (“If the Bulldogs win the game”) and B is a statement (“They will go to the playoffs”). The first statement is called the “antecedent”; the second is called the “consequent.” “A → B” (the first line) is the major premise of the argument; “A” (the second line) is the minor premise. The third line, “Therefore, B,” is obviously the ar

It is important to be aware of the difference between truth and validity. Though often confused, they are in fact quite different. First, truth has to do only with statements, whereas validity has to do only with that structural arrangement of statements that we call an argument. Second, a statement is true if what it asserts reflects what is objec

Note this about the “completely unlike” judgment: No two things can be so unlike that they do not share the elemental act of existence. If, in comparing A and B, it is declared that B is “totally unlike” A, then there would be but one thing, A, since B would not exist.)

The affirmative statement is more direct and emphatic. (This is true of all affirmative statements.) Because its emphasis is on what is the case rather than on what is not the case, it elicits a positive response.

But it is possible for particular statements to be quite precise: “Sixteen percent of the runners finished the race in under two hours.” Always be as precise in your statements about things as your knowledge of them allows you to be.

So long as the entire class is not being referred to, the statement is particular. Be it large or small, a portion is a portion.

The most effective argument is one whose conclusion is a categorical statement. A categorical statement tells us that something definitely is the case.

Aristotle’s pithy two-word definition of man—the rational animal—has gained classical status. “Animal” is the proximate genus; “rational” is the specific difference.

When we define something, what we are attempting to do is simply identify it more precisely—first by grouping it with other things that are generally similar to it, then by noting what is unique to it (the specific difference) in comparison with the other things in the group.