“In God we trust; all others must bring data.” -W. Edwards Deming
Riporto tre obiezioni, tutte varianti del self-defeating argument (che risale alla critica platonica – Teeteto, 171 a-c – e aristotelica – Metafisica, 1006 a-b – a Protagora), alla persuasione relativistica, tratte da Truth di Pascal Engel (pp. 142-3). Niente di nuovo, certo, ma in tempi di vattimismo imperante (imperdibile il sito “Filosofi precari.it, ovvero: l’unica maniera di resistere alla società neoliberale” – perchè il neoliberismo, si sa, rende il filosofo precario) e tremontismo di ritorno, meglio tenerli a portata di mano. Si sa mai.
The best way to formulate it [the relativist thesis] is to note that for the relativist, two statements that contradict each other can both be true if they are made from a different perspective or point of view. Hence the following situation is possible:
(1) p (relative to my system, say S1)
(2) not p (relative to yours, say S2)
(3) hence: p(S1) and not p(S2) is true
But this claim is incoherent. For the very statement that p(S1) and not p(S2) can be true must itself be true relative to some system: p(S1) and not p(S2) (relative to S1). So relativism cannot even be stated.
A second objection concerns the meaning of p and not p, when it is said, in the manner of (3), that they can be contradictory, but nevertheless both true with respect to each system. The very possibility of sayung this supposes that we can understand these sentences and what they mean. But if their meaning depends upon their truth conditions, there must be something common to the two sentences, namely these truth conditions, and if these can be invariant, truth itself cannot vary so radically from context to context.
A third and related objection is that relativism cannot be stated if it amounts to the thesis that:
(4) p is true relative to a person P or a community C iff P or C believes p.
But the fact that P or C believes p is either a relative affair (they believe p by their own lights, so to speak), or it isn’t. If it isn’t then there is no way to formulate the proposed condition. And if it is, then there is at least one absolute truth about what P or C believes.