Predication and the Copula

In one line

Predication is the act of asserting something of something, and the copula is the word that carries that assertion.

In the wording a student can write in an examination: predication is the joining of a predicate to a subject in an assertion; the copula is the sign of that joining, expressed in English by "is", "are", "is not" and "are not". The copula carries the quality of the proposition and asserts a relation, not a time.

What predication is

Every categorical proposition does one thing: it takes something and says something about it. The something is the subject; the something said is the predicate; the saying is predication.

That is not as empty as it sounds, because two things follow immediately.

Predication is an assertion and not a naming. "The registered document" names something and asserts nothing. "The document is registered" predicates registration of the document, and is therefore true or false. This is why a term is not a proposition, at sequence 170, and it is the whole difference.

Predication is what the copula performs. Remove the copula and there is no assertion left, only two terms lying side by side.

The copula and its three functions

It joins. The copula is what makes two terms into one proposition. This is the function it is named for: copula is Latin for a link.

It carries the quality. Affirmative or negative is settled in the copula and nowhere else. "Is" affirms and "is not" denies, and reduction to logical form, at sequence 300, requires any negative to be brought into the copula.

It asserts. The copula is the sign that the speaker is committing themselves. In a conditional, where nothing is asserted, the copulas of the antecedent and consequent are present but the whole is not asserted, which is why sequence 290 insisted that a conditional asserts neither part.

What the copula is not

It is not a term. It is syncategorematic, as sequence 170 established: it has no meaning standing alone and can be neither subject nor predicate. A student who counts three terms in "All contracts are agreements" has counted the copula as one.

It does not assert existence. "Is" in the copula is not the "is" of existence. This is the point that connects to the last chapter: reading the copula as an assertion of existence is precisely what gives universal propositions their traditional existential import, and it is what the modern scheme rejects.

Above all, it does not indicate time. This is the point MU's phrase "with special reference to the copula" is pointing at, and it deserves its own section.

The copula is timeless

The copula is always written in the present tense and it never means the present time.