They further maintain that one of the two premises may at times be omitted—either because it is already known or for some ulterior, unsound purpose—and they divide the composite syllogism into a “separated” and a “connected” form, as mentioned earlier.
We reply: This is an admission on your part that some conclusions require several premises, while others can be established with only one. You have also conceded that whenever more than one premise is required, the situation really amounts to several syllogisms. In that case, if you insist that what is strictly indispensable is a single syllogism comprising two premises, and that anything beyond those two constitutes additional syllogisms used to prove each of the original premises, then you should just as well concede that what is indispensable is one premise, and that whatever premises are added beyond it serve merely to clarify that single premise.
This is closer to sound reason. When the ascription of an attribute to its subject—when the judgment to the thing judged or the predicate to the subject—is unknown except through a middle term that functions as evidence, the only unavoidable element is one premise; anything extra may or may not be needed.
To claim that a two-premise syllogism is necessary because some questions require it is no different from claiming that three, four, or even five premises are necessary because other questions require that many. Fixing any specific number is no more warranted than fixing another. Likewise, their talk of omitting one of the two premises because it is obvious, or in order to mislead, finds its counterpart in omitting a third or a fourth premise.
Whoever argues a point with a single premise that is insufficient to establish the desired conclusion—or with two or three insufficient premises—must be pressed to supply whatever completes the proof. Once the premises are produced, any that admit rejection are to be rejected, and any that invite objection are to be challenged, until the reasoning is sound and complete, just as one who