Relativism about truth or alethic relativism starts with the claim that the truth of a proposition does not depend just on how things are in the world, as realists would claim, but also on some additional parameters such as the standard of taste, contexts of assessment, perspective or a framework. Relativists believe that such parameters could vary between individuals and groups, and that there are no known relative overarching standards of evaluation. So, the same proposition may turn out to be true according to one parameter and false according to another. These conflicting verdicts are equally valid. Relativism about truth is the broadest and strongest form of relativism available. In fact, the various versions of local relativism, for instance, relativism in the epistemic or the moral domain, can be restated as claims about the relativity of truth in those domains. Alethic relativism is as old as Western philosophy, as it made its first appearance with Protagoras of Abdera in the fifth century BCE. It has been recently developed within analytic philosophy. We will consider it in both it's old and in it's contemporary versions. To begin, let's hear from Casey Perin, Associate Professor of Philosophy at the University of California Irvine, on how you would characterize Protagoras' relativism. Protagoras's relativism has three important general features. First, it's a relativism about truth and more precisely about the truth of a person's perceptions or beliefs. Secondly, it's a relativism that relativizes the truth of those perceptions or beliefs not to a culture or a society or a social group, but to an individual human being. So, in a bit of writing we have from Protagoras, he says that a human being is the measure of all things: of those things that are, that they are, of those things that are not that they are not. Finally, Protagoras's relativism is global rather than local. That is, it's a relativism about all trues in all domains rather than about the trues just in a particular domain, like the domain of ethics or etiquette. Both Plato and Aristotle thought that Protagoras' relativism was false, but they both thought it was a view that was important enough to target for refutation. In his dialogues with Theaetetus, Plato rehearses a wide variety of objections to Protagoras's relativism. So he argues, for instance, that if Protagoras's relativism is true, then no one person is wiser or has more knowledge than any other person, and so no one is an expert and this includes, of course, Protagoras himself. But maybe Plato's most important argument against Protagoras and his relativism is that the relativism is self-refuting. Now the details of the argument are controversial but very roughly, the idea is this: if you assume the truth of relativism and you add to that the fact that seems undeniable that some people think relativism is false, Plato argues you can get from there to the conclusion that relativism actually is false. Aristotle had a different objection. He thought that if relativism were true, then all contradictions were true. But he thought it's clearly false that all contradictions are true. So, Protagoras' relativism must be false. I think it's fair to say that few philosophers today would endorse Protagoras's global relativism. I think it's also true that most philosophers today would agree with Plato that Protagoras' relativism is self-refuting and so incoherent. They might disagree with Plato about just how to formulate the self refutation argument against Protagoras, but they would agree that something like the self refutation argument holds against Protagoras's relativism. They would also agree with Plato that local versions of relativism restricted to something like the domain of morality or to etiquette is at least coherent, that is, self refutation argument wouldn't work against those restricted forms of relativism. To say it's coherent, of course, is not to say that it's true but it's at least not self-refuting. We now consider a contemporary alethic relativism, as it has been developed in the last decade within analytic philosophy. Consider "licorice is tasty". This sentence seems to concern a subjective matter, for tastes vary from person to person. According to professor of philosophy at Vienna University, Max Kolbel, it is an example of relative truth. It is true if for instance speaker say standards of tastes are operative and is false if speaker's based standards of tastes are operative instead. If so, then A and B disagree, but their disagreement is faultless. Neither of them has made a mistake. Professor of Philosophy at Berkeley, John MacFarlane, has proposed another kind of alethic relativism. The difference with Kolbel is that who occupies the contexts of assessment need not be either of the speakers, would take part in a dispute about taste, but it may be a third person who assesses their dispute from her own contexts of assessment. The contexts of use and assessment often coincide, for it is natural to consider the speaker as the privileged assessor of her own utterance. Yet, the contexts of assessment and the contexts of use may differ. So, the preposition expressed by A's utterance of "Licorice is tasty" may be true according to A's assessment. False according to B's assessment. True according to my own assessment or yours and so on. It can be false for A too if A later comes to occupy a different context of assessment because their taste has changed. In that case, A could actually retract her previous assertion as is now false given the standards operative at her new contexts of assessment. Next, we will explore some of the limits of alethic relativism. Kolbel's proposals saves faultless. Each subject is speaking truly given they're respecting standards of assessment. Yet each of them is judging the liqorice is or isn't tasty from within a different contexts of assessment. This makes it difficult to make sense of the idea that they are really disagreeing with one another, for disagreement would seem to depend on occupying the same context of assessment and on reaching different verdicts. Furthermore, Kolbel's proposal does not seem to be able to offer an account of the possibility of retraction. For if they're relevant standards are the ones which were operative at the context of use, then in so far as ones earlier judgment was accurate, that is, it reflected ones preference back then, it was correct and still is. Macfarlane's proposal, on the other hand, does not save faultlessness because given a specific context of assessment, it is true or false absolutely that the licorice is tasty. It does not respect disagreement either if disagreement is meant to depend on occupying the same context of assessment and don't returning different verdicts on a given issue. It may save it though if disagreement is taken to straddle contexts of assessment. It can also save retraction since from the new contexts of assessment, the subject can deem one's previous judgment wrong.
