[Sidenote: Subject, predicate, and copula, what they are, and abstract and concrete what.] 3. Wherefore, in every proposition three things are to be considered, _viz._ the two names, which are the _subject_, and the _predicate_, and their _copulation_; both which names raise in our mind the thought of one and the same thing; but the copulation makes us think of the cause for which those names were imposed on that thing. As, for example, when we say _a body is moveable_, though we conceive the same thing to be designed by both those names, yet our mind rests not there, but searches farther what it is _to be a body_, or _to be moveable_, that is, wherein consists the difference betwixt these and other things, for which these are so called, others are not so called. They, therefore, that seek what it is _to be_ any thing, as _to be moveable_, _to be hot_, _&c._ seek in things the causes of their names. And from hence arises that distinction of names (touched in the last chapter) into _concrete_ and _abstract_. For _concrete_ is the name of any thing which we suppose to have a being, and is therefore called the _subject_, in Latin _suppositum_, and in Greek ὑποκέιμενον; as _body_, _moveable_, _moved_, _figurate_, _a cubit high_, _hot_, _cold_, _like_, _equal_, _Appius_, _Lentulus_, and the like; and, _abstract_ is that which in any subject denotes the cause of the concrete name, as _to be a body_, _to be moveable_, _to be moved_, _to be figurate_, _to be of such quantity_, _to be hot_, _to be cold_, _to be like_, _to be equal_, _to be Appius_, _to be Lentulus_, _&c._ Or names equivalent to these, which are most commonly called _abstract_ names, as _corporiety_, _mobility_, _motion_, _figure_, _quantity_, _heat_, _cold_, _likeness_, _equality_, and (as Cicero has it) _Appiety_ and _Lentulity_. Of the same kind also are infinitives; for _to live_ and _to move_ are the same with _life_ and _motion_, or _to be living_ and _to be moved_. But _abstract names_ denote only the causes of _concrete names_, and not the things themselves. For example, when we see any thing, or conceive in our mind any visible thing, that thing appears to us, or is conceived by us, not in one point, but as having parts distant from one another, that is, as being extended and filling some space. Seeing therefore we call the thing so conceived _body_, the cause of that name is, that that thing is _extended_, or the _extension_ or _corporiety_ of it. So when we see a thing appear sometimes here, sometimes there, and call it _moved_ or _removed_, the cause of that name is that it _is moved_ or the _motion_ of the same.