Everything is relative, especially incest. Minus the admittedly lame humor, this seems to be the motto of most people in contemporary society. I beg to differ.
What most people mean applies to anything more or less controversial: morals, politics, religion, most of all truth. The notion, which stems from the humanism of the Renaissance and the Protestant Reformation alike, is that human beings are, individually, the arbiters of everything.
The almighty I knows what is right and wrong, what political party governs best, what God is like and what is true. This is based on the epistemological fallacy of the day: I can know everything and I am always right, for me at least.
False! Mistaken! Wrong-o, moosebreath!
I do not and cannot know everything. Knowing everything that human beings can observe empirically and prove scientifically has not been possible for any single human being since about the time of Demosthenes. In ancient Greece it was possible to hold in one brain all human knowledge. Today there are idiot savants who can hold a preponderance of human knowledge in their brains, but they can't do much with it of any use.
I am not always right. Much for the same reason, people cannot have the correct answers to every possible question. We just don't know.
Besides, many things remain unknown. Things that count: Does God exist? What's God like? (Yes, I know the one about the astronaut who told the Pentagon She was Black.) How did the universe begin? How large is the universe? Are there other intelligent sentient beings out there? What's the telephone number of an honest, cheap plumber?
Also, observation and empirical facts do not necessarily equal the truth. Human perception is fallible and limited; facts are dependent on context (I'm told, for example, that gravity does not work the way you would expect at the quantum level.)
Intuition and nonlinear thinking may capture ineffable instances of truths that are not observable, measurable, much less communicable.
Despite all this, I would contend that there is truth, a grand unifying truth that explains everything. We just don't know it.
At least, it's pretty clear that if there is truth, it is absolutely true; it is true everywhere, for everyone, in every context. Truth is the absolute, universal, incontestable statement about everything that transcends contextual and perception limits.
Its opposite is not truth. It may be falsehood, error, a lie.
Anything less than truth, by degree, omission or approximation, is not truth. Anything that is true for me, but not for you, is not truth; it may be a fact, a hunch, a strong feeling, an opinion. Not truth.
I don't know the truth. Not knowing the truth, I have no grounds to try to bash in your face simply because your idea of morals, politics, religion and truth differ from mine. It might be a good idea to be tolerant of one another.
But that doesn't make your idea or mine true. Much less both true. One of us is closer to the truth (probably me, since this is my blog).
Both of us cannot assert that our opposed and incompatible ideas are equally true, although we may deserve equal respect when we spout our nonsense. (By "our," to paraphrase Steve Martin, I mean "your.")
"Everything is relative" is an absolute statement. If it were a relative statement, compliant with the idea that everything is relative, it would be false.
If everything is relative, then the idea that everything is relative must itself be relative, meaning -- for example -- that everything might be relative for me, but not for you.
Everything cannot be relative. Only incest, Thanksgiving dinners, gifts of underwear, people one cannot divorce despite one's most earnest wishes, the price of postage stamps and a few other things.