A Refutation of Subjectivism
The quintessence of language is the communication of information. When human beings communicate, at all but particularly using the tool which is language, information representing the world in which humans exist is being transmitted from one human being to another human being. This would not be possible if every human did not exist within the same world—this world—for if each human existed within a world independent all other humans, then humanity ceases to exist for lack of accessibility to the context which birthed any and all things subject to that existence, meaning that which is each and every extant thing within its own particular existence (assuming, necessarily, the theoretical possibility of other existences).
Of course, humans do indeed exist, for these words are being written by a human, to be read by other humans, for the purpose of communicating information from one human (me) to other humans (you). This is the leap of faith intrinsic to the human existence: that a world beyond self actually exists and is not only just perceived to exist, say, as a figment of the imagination. And, if it is, then what are we? Me? Although, one must completely suspend belief in all else to believe this—as well, even the possibility of belief, and this is nothing if not counterproductive to any and all grasps at knowledge. Even the subjectivist must concede this, not only theoretically, but actually.
Moreover, humans are observed to be universally comprised of many exclusive qualities that altogether taken into account form the cognitive basis for the conceptual human; and, therefore, one distinguishes within the mind for oneself that which is humanity, apart all other forms of life and any other thing, in relation to self. One of these exclusive qualities is the capacity for language. Language is the mechanism having evolved within humans for humans to communicate information to each other (and to other species, as well, though to a much lesser extent) in observation of what is generally presumed to be the same universally perceived reality. What is observed of this reality seemingly implies that a fundamentally inconsistent reality (the implication of subjectivism) would be incapable of yielding (much less, sustaining) the myriad, inextricable systems functioning altogether as a single cosmic system, whereof one observes this of this reality.
Language is information, or data, that is a representation of this reality, intended to communicate one perception of reality, made by one human being, to any and all other human beings, presumably for the sake of cooperating as a species in order to survive and navigate the world in which humanity exists, as seems to be the imperative of all life. The essence of this existence seems to be its consistency, therein reflected in the very concept of language. In other words, language would not be possible were it not for the consistency of the underlying fundamental reality it necessarily comes to reflect—a reality that must remain consistent through time and space—whence arises the very notion of truth.
Truth can be only that which remains consistent across time and space, as in that which is the reality represented by the data being transmitted from one perceiver to the next, as this be the only way for a thing to have been said to ever be true; otherwise, the concept of truth is fundamentally compromised. Not only is this conceptually true—if this were not actually true, then nothing at all is possible, because nothing at all would exist, as it would lack the ontological consistency to ever be a thing, even if that thing were never at any two points the same thing. This is not only to say that nothing would exist, as the implication is far worse, for the nothing exists only in contrast to the thing—anything—so long as it is something, such that the concept of the nothing retain its conceptual value: truth.
Truth is the fundamental axiom of existence. I think, therefore I am. If one is to be certain of anything, it is that which is professed by the Cogito. Thus, one has the something (as opposed to the nothing) and, therefore, the basis for truth, upon which is based any and all knowledge, including even the possibility of knowledge. The only epistemological relevance possessed by that which is subjectivism is in relation to perspective and value, but only ever within the context of truth. For existence to have any meaning whatsoever, even to the subjectivist, truth must be held to be a thing independent that of any perceiver. Otherwise, existence itself would remain unintelligible and forever beyond the grasp of any one single entity within existence.