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.)

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.

Vague and ambiguous words and expressions wander about among various ideas instead of settling definitely upon one or another particular idea.

There are two basic types of objective facts, things and events. A “thing” is an actually existing entity, animal, vegetable, or mineral. The White House is an example of the first type of fact, and the assassination of Abraham Lincoln of the second. The first type is more basic than the second because events are made up of things or of the actions

We sometimes take it for granted that an audience is aware of background information that is necessary for a correct understanding of the subject we’re speaking on, but in fact the audience may be quite innocent of this information. When in doubt, spell out the background information. It is always better to err on the side of saying too much than

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.

One thing is said to be the cause of another thing because (a) it explains the very existence of that thing, or (b) it explains why the thing exists in this or that particular way, the “mode” of its existence.

Logical truth, as you might suspect, is the form of truth we are most directly concerned with as logicians. Logical truth is simply the truth of statements.

Truth has two basic forms. There is “ontological” truth and “logical” truth. Of these two, ontological truth is the more basic. By ontological truth we refer to the truth of being or existence. Something is said to be ontologically true, then, if it actually exists; it has real being.