"Relativism" is one of those words that gets thrown around in our culture a lot, but we don't always clarify what we mean by it. In particular, it gets used by conservatives as a slur--often to discredit a view that seems too fuzzy: "That seems dangerously relativistic to me." On the other hand, I've talked to at least two people in my life who did claim to be thorough-going relativists (one was a philosophy Ph.D. student at Duke, the other was an eccentric elderly gentleman, also with a philosophy background but not a member of the academic establishment, whom I met in Barnes and Noble). Neither of them gave what seemed to me like a convincing answer to the objection that their position undermined any kind of moral judgment. They both (particularly the guy in Barnes and Noble) appeared to endorse a code of ethics that relied primarily on leaving one another alone and respecting the rights and privacy of others. But neither of them seemed to be able to answer (to my satisfaction at least) my objection that if there are no absolutes then this code itself has no valid basis. Furthermore, any thorough-going relativism exposes itself to the old stand-by: if there are no absolutes, then it is absolutely true that there are no absolutes.
Precisely for this reason, I think we need to take more seriously a much more modest kind of relativism (one could call it "relative relativism") which fulfills the need felt by relativists (for acknowledging the limitations of our viewpoint as limited human beings) without falling prey to the charge of self-refutation. An old friend of mine in college put it best: in this kind of relativism, what is being claimed is simply that everything we know or affirm to be true is known and affirmed from a particular standpoint, influenced and shaped by particular circumstances. (I'm paraphrasing him, not quoting him.) This does _not_ deny that there are absolute truths. Nor, in a sense, does it deny that we have access to those absolute truths. But our access is not itself absolute. We know the absolutes, but we do not know them absolutely. This, it seems to me, is true to the Thomistic maxim that knowledge exists according to the mode of the knower, and to the far more important Pauline saying that we "see through a glass, darkly" in this life.
This results in a paradox. I can see with utter conviction that certain things are absolutely right and wrong, while remaining aware of the fact that I am speaking from a particular perspective, shaped by particular influences. I can be at least somewhat self-aware in this regard, and will naturally be more confident of the absolute relevance of what I'm saying insofar as my perspective appears to be that of the human race as a whole, or at least of a large cross-section thereof. From a purely rational point of view, it is far more certain that cruelty is wrong than that democracy is the best way to govern human beings, and it is far more certain that a God of some kind exists than that God is Three Persons in One, and that the Second Person of the Godhead became man for our salvation. This is primarily relevant in terms of our attitude toward those with whom we disagree. Contrary to what both thorough-going relativists and some Christian advocates of "total depravity" would argue, the Nazis for instance were aware that what they were doing to the Jews was cruel (or, as they would have said, apparently cruel) and went against certain basic human moral intuitions (they argued these moral intuitions away, but the very arguments they made showed that the intuitions were not simply absent). Absolute monarchy, on the other hand, was regarded as a positive good by many people throughout history, and we should be very cautious about judging those who accepted this belief, even if we strongly believe otherwise.
As I suggested in a comment to an earlier post of mine, this is somewhat relevant to the old story of the blind men and the elephant. We do in fact see only in part, but that does not mean that our knowledge is purely subjective, or that all knowledge is equally valid. One poster, "Basil," objected in a further comment that this leaves out the fact of revelation. If the "elephant" has revealed Himself to us, then the analogy no longer works. I don't think this is true, because of the Pauline and Thomistic principles I've already mentioned. Even revelation is received according to the mode of the knower. This is why certain Protestant understandings of the perspicuity of Scripture are simply false to reality. A certain kind of Catholic apologetic rightly points this out, but then lands itself in the trap of trying to eliminate the limitations of the "through a glass" perspective via an infallible magisterium. As I've already said on this blog, I'm simply not convinced that this epistemological strategy works.
Christianity is necessarily rooted in particularity. We believe it either because it was taught to us from infancy or because at some point, due to particular circumstances, it commended itself to us as true and good. (For most of us it's some combination of the two.) This does not negate the universal claims of Christianity. But it should affect how we express those claims, and how we regard both non-Christians and adherents of forms of Christianity other than our own. We have no direct access to some kind of God's-eye perspective from which to evaluate our own beliefs vis-a-vis other ways of seeing the world. This should not be a reason for discouragement or cynicism. This is the way God made us to know the world--through eyes of flesh and with a brain made up of little gray cells, subject to headaches and chemicals and hormones. To try to transcend this perspective is to try to transcend our humanity.