If you say: "Nothing is absolute, everything is relative". Then you make an absolute statement. How can this be?
Jack Meiland advances an interesting argument to the effect that in affirming the truth of relativism, the relativist is not necessarily caught in self-contradiction. The relativist only needs to be careful :
That relativism is self-refuting... is a myth which must be laid to rest. It would be inconsistent for the relativist to say both that all doctrines are relatively true and that relativism is not relatively true but instead is absolutely true. However, the careful relativist would not and need not say this. He would either say that all doctrines except relativism (and perhaps its competitors on the meta-level) are relatively true or false, or else he would say that his own doctrine of relativism is relatively true too. And saying that relativism is only relatively true does not produce inconsistency. (Meiland: 'On the Paradox of Cognitive Relativism', 121.)
But is 'relatively true' a coherent notion ? That depends on the coherence of the notion of 'relative truth'. Meiland confronts and seeks to vindicate this coherence :
(1) The concept of absolute truth seems to be a concept of a two-term relation between statements (or perhaps propositions) on the one hand and facts (or states of affairs) on the other. But the concept of relative truth, as used by some relativists, seems to be a concept of a three -term relation between statements, the world, and a third term which is either persons, world views, or historical and cultural situations.
(2) The relation denoted by the expression 'absolute truth' is often said to be that of correspondence. The relativist can make use of this type of notion and say that "P is true relative to W" means something like "P corresponds to the facts from the point of view of W (where W is a person, a set of leading principles, a world view, or a situation) (Meiland: 'Concepts of Relative Truth', 571.)
Meiland offers at least a prima facie plausible and not run of the mill defence of the relativist against the charge of self-contradiction. I offer it as such. Of course it will not emerge unscathed, or possibly at all, from PSE critique. But such is the way of philosophy.
Jack W. Meiland: 1979, 'Is Protagorean Relativism Self-Refuting?', Grazer Philosophische Studien 9, 51-68.
Meiland: 1977, 'Concepts of Relative Truth', The Monist 60, 568-582.
Meiland: 1980, 'On the Paradox of Cognitive Relativism', Metaphilosophy 11, 115-126.
Meiland: 1973, 'Cognitive Relativism: Popper and the Argument From Language', Philosophical Forum 4, 406-421.
Jack W. Meiland and Michael Krausz (eds.): 1982, Relativism: Cognitive and Moral, University of Notre Dame Press, Notre Dame.
Harvey Siegel, 'Relativism, Truth, and Incoherence', Synthese, Vol. 68, No. 2, Issues in Epistemology (Aug., 1986), pp. 225-259.
James N. Jordan: 1971, 'Protagoras and Relativism: Criticisms Bad and Good', Southwestern Journal of Philosophy 2, 7-29.
If we know only about the material world, your statement is true. Then you can take your doubt as an exceptional case. But if you know the Truth, you can't say that statement. So, it is definitely wrong. You can correct it like this:"Almost everything is relative. But something is absolute."
You may read page 1 & 2 of https://www.allaboutphilosophy.org/absolute-truth.htm
You might have read this statement: "Nothing surpasses the truth; it is above all!"
Great men wouldn't have used the term--"The Absolute" if there were no such thing.
You are objectively correct. If all things are relative then making this claim will prove objective knowledge is absolute and exist. The term absolute and objective both express that the truth value of a proposition is impossible to change. Perhaps you wrongly use the Wrong name for the same substance. This does not change a truth value alone. Consider "all women are human beings" this is impossible to be false and as such is an objective claim. This clearly puts a whole in the original proposition all things are relative. If I say all humans are 3 feet tall and find a man taller than 3 feet there is an issue: either this is not objecrively a man or there is a poor description or rule about all human beings. Deductive reasoning done correctly does not allow exceptions whatsoever. The exception objectively proves the rule or claim false. If I say all swans are white and someone discovers black swans elsewhere my original claim is false. The exception emotional claim is usually done in a superior to inferior human relationship. That is i can do x but you cannot do x. Do as I say not do as I do. This has nothing to do with deductive reasoning as you can see. As I think of it I find it hard to use exception in the direction from a subordinate to a superior.
Proper and rational communication would require the speaker to be as specific as possible to prevent misinterpretation. This is why there are rules of how to use propositions and you can't just do what you like. This is not standard or mentioned frequently. The subject and predicates ought to concrete nouns. That is no adverbs or adjective endings in your sentences. This is to reduce deception and misinterpretation. You writing vague sentences or open sentences is a rhetorical device to ensure you have a comeback line when someone calls you out on your shady reasoning. All and NO are quantifiers that express 100 percent. If I say all dogs are mammals I mean 100 percent of the dogs are mammals not 98 percent. No birds are reptiles means 100 percent ( or you can use zero) of birds are reptiles. To mean less than 100 percent you would use SOME. You have a positive Some s are p or the negative some s are not p. There is no majority of, a few of, etc. We agree probably this is not so persuasive practically so we speak differently.
It's a phrasing that makes you think. It could be that the speaker believes there is an absolute and is lying. The reason for lying is outside of the scope, though convincing you to dislodge yourself from a position in a surrounding debate is one answer.
There is, however, another answer. Phrases like "Nothing is absolute, everything is relative" are just strings of characters. They have no more meaning than, say, "gaba go go mona doo da," unless they are interpreted with respect to an individual's interpretation of the language. Only then do they have meaning. This, of course, means the meaning of that phrase must be with respect to something in the speaker's mind. If one assumes that that individual truly does believe everything is relative, then there are only relative things in that speaker's mind -- no absolute things to which the phrase can ascribe a meaning.
Of course, what the speaker means in such a context is not sufficiently specified to permit rewriting the phrase in absolute terms with an absolute meaning.