Can we know truth? Ironically, the answer may be in the question. Consider the statement: "All truth is relative." In fact, some truth is relative. "The sky is blue" might be relative to your location and the time of day. "Joe Montana was a great quarterback" is true today, but it wasn't in 1935. This statement is relative to time. To assert, however, that all truth is relative is a self-denying, absurd statement. If all truth is relative, then we can't be sure that that statement is true.
When someone says, "Truth is relative," I want to quickly reply, "How do you know?" If we agree with this sort of relativism, then we must accept that this very statement is also relative. It's only fair and accurate to say that some truth is relative. Any other view is logically contradictory.
Further, there are some statements that humans inherently know to be true. Is it true that 2+2=4? Denying that statement is similar to denying many other clearly truthful statements. People often play all sorts of semantic games to avoid committing to absolute truth, but not believing in the basic principles of addition does not make them false. Frank Beckwith made this interesting comparison,
"...we can rationally discuss and argue with each other about right and wrong without resorting to the claim that ethical judgments are merely subjective or relative and that all such judgments have equal validity. For to claim the latter logically leads one to the bizarre judgment that Mother Teresa is no more and no less virtuous than Adolf Hitler." 1
If this concept is difficult for you, take a closer look at the Argument by Morality. There simply are things that are right and wrong, true and false. Likewise, as stated above, some things truly are relative, but only some. Naturally, if some truth is relative, then some truth must be absolute. How can we know truth? How can it be identified? That is clearly the most significant question. Which truths are the relative ones and which are absolute?