The phrase “subjective truth” is an oxymoron. If something is a truth, then it is simply true and we can leave out the word “subjective.” If we have a string of words that do not express a truth (e.g. “Oh yum!”), then we may want to use the word “subjective” but we can leave out the word “truth.” Consider ordinary cases where someone might say that a truth is “subjective”:

(1)
Alex’s favorite color is green.
(2)
Joe prefers vanilla ice cream to chocolate.
(3)

Supposing that it really is the case that Alex’s favorite color is green, that Joe really does prefer vanilla, and that Adam really did receive a B, all three of these sentences express simple truths. These are simple facts about the world, the same world that we all live in. If (1) is true, then there is a person named Alex and he really does have a preference for the color green. The fact that Alex has a friend who prefers purple does not alter the truth of (1) at all, it simply makes a completely different proposition true:

(4)
Alex’s friend prefers purple.

What is more, Alex’s friend does not make (1) half-way true or “kinda” true. Propositions (1) and (4) are both simply true, and their truth is completely compatible with one another just as much as the truth that “four and six makes ten” is completely compatible with the truth that “two and two makes four.” Obviously, the subjects “Alex” and “Alex’s friend,” are central to the meaning of (1) and (4), and so we may conclude that “subjective truths” are simply objective truths that include a reference to subjects, but that is hardly what people usually mean. It would be much easier to simply talk about truths that refer to people and truths that do not.

This suggests, however, another way that we may understand the idea of “subjective truths”: Perhaps there are sentences that do not include a reference to a subject, but that lack a truth value without such a reference and furthermore change their truth value depending on which subject we supply. Consider what would happen, for instance, if we deleted the reference to Joe in (2) and massaged what is left into something grammatically acceptable:

(2$$\prime$$)
Vanilla ice cream is preferred to chocolate.

Now we could simply interpret such a sentence as saying, “There is some subject $$S$$ such that $$S$$ prefers vanilla ice cream to chocolate,” in which case (2$$\prime$$) would be entailed by (2). Or we could interpret it as saying that all people, or nearly everyone, or most, have such a preference, but with all these options we are still simply left with plain old truths about the preferences of a population—more simple facts about one and the same reality. But we could also interpret (2$$\prime$$) in such a way that it is neither true nor false until we supply an answer to the question: “Preferred by whom?” If we supply Alex, who prefers chocolate, then the sentence comes out false, but if we supply Joe, the sentence comes out true. But again, the notion of subjective truth does not really help us here. Before we supply the missing subject, we do not have a truth at all. We simply have an incomplete thought that requires further expansion before we can evaluate its truth value. Although the words form a grammatically complete sentence, they do not indicate a logically complete proposition.