Knowledge of Related Truths: Revisited

A friend of a friend is interested in apologetics and wanted to along the argument I presented in this post to her philosophy professor. I don't know whether or not he is a Christian, but here was his ostensible reply:

One of the problems I saw immediately in the argument was his use of “proposition”. A proposition is a component of an argument, He states: "Are all propositions related, or can a proposition be known to be true in isolation from all others?" A proposition cannot stand alone to begin with. There must be at least two propositions in an argument: premise and conclusion is the simplest argument. To stand alone it must be one of three things: a statement, a command or an exclamation. His questions at the ends of the first paragraph – can a proposition be known to be true in isolation from all others – makes his argument problematic from the beginning.

To be honest, I'm not even sure how this response relates to the points I made in the post, so I guess I'll just post a few thoughts:

I am in full agreement that propositions are only components of arguments. But knowledge is propositional. The nature of the object of our knowledge (propositions) is a separate issue from the nature of the justification of our knowledge (argumentation).

I also agree with the idea propositions cannot stand alone... that was a point of my post. That propositions cannot stand alone is instrumental to the argument I made, viz. ignorance of one proposition begs the question as to how one can know any proposition. The conclusion I drew was essentially that recourse to an omniscient source for knowledge is an epistemic necessity. In any case, I wasn't just asserting that as an isolated, true proposition. I clearly argued for that. So exactly how this is "problematic" needs to be explained.

As a side note, the idea that statements, commands, and/or exclamations can stand alone is vague. As I wrote in this post:

It is true that assent to the isolated statement “Jesus is Lord” does not necessarily mean that one knows its biblical meaning; he may be assenting to a falsehood. But the point is that one doesn't need to know the biblical meaning “in the context of all other propositions” in order to know what God knows. It is sufficient to know the infima species of the biblical subject “Jesus,” i.e. a minimal, finite number of propositions which would individuate “Jesus of Nazareth” from “Jesus of Strauss” et. al.

The English language is infamous for its imprecision, ambiguity. Take the professor's assertion, for example. What does "stand alone" mean?

Does he mean that certain sentences can be written or said without need of elaboration or a context for understanding these sentences? That doesn't make much sense. Just as the statement "Jesus is Lord" is unintelligible if abstracted from a context in which the statement can be understood, if I command one to "obey God," he might reasonably ask what "God" I am referring to. I had better be able to appeal to a broader context.

Or maybe the professor means that these sorts of sentences require no epistemic justification? But how would that be relevant? Knowledge is propositional. Propositions are the meanings of declarative sentences. I can say "Joe was he who hit the ball" and "the ball was hit by Joe" and those two sentences mean the same thing. To know the proposition is to understand both sentences. Commands cannot be known, because commands have no truth value. "Obey God" is neither true nor false. It may or may not be true that "one ought to obey God." Furthermore, propositions can be conveyed via "exclamations" and statements," so I really have no idea what the professor means by "stand alone."

Regardless, it doesn't appear to me that the professor understood the argument I was making. If he really did understand it, I am disappointed he didn't write a clearer, more thorough critique. I don't mind being shown I'm wrong, if I am wrong. At the same time, I hope that the friend of my friend won't be so easily taken in by such a reply as this.