Can Truth be Relativized to Kinds of Mind?

Abstract

Nicholas Unwin has recently claimed that truth is an essentially relational concept; relative, that is, to the type of brain the author of the relevant assertion has.1 In startling contradiction to how truth is standardly conceived, he argues that it can be consistently maintained both that A truly said that the earth is round, and that B truly said that the earth is flat. The key is supposed to be that A and B can by their assertions be expressing different relations to the earth, if they have different cognitive processing mechanisms (CPMs). For according to Unwin, in making assertive claims one is not asserting the speaker-independent truth of a proposition as traditionally conceived, and thus demanding the agreement of any rational being, one is only demanding the agreement of beings with CPMs similar to one's own. He proposes to distinguish the objects of assertions from their contents, so that even if the propositional content of assertions by A and B is the same, the objects-which for Unwin are the speech-acts of assertion themselves are different. Thus beings with different CPMs could both say that the earth is round, yet one assertion might be true and the other false. In one sense, this analysis would seem to make truth a communal concept, involving a relation between a particular speech-act of assertion and a certain class of cognitive beings. It may be tempting, then, to compare Unwin's treatment of truth with Kripke's community-relative analysis of rule-following and meaning,2 and with Welbourne's recent, apparently similarly communal, account of knowledge.3 But in another sense, Unwin's analysis is not essentially social or communal, since the assertor need not interact with any other being with a similar CPM-he may not know who have such CPMs, or even that anyone does. The relativity of truth could equally well be said to be to a type of CPM, rather than to the set of beings who actually instantiate it. Even if Welbourne and Kripke retreat under pressure to saying only that the knower or rule-follower must be considered as potentially in interaction with a community, Unwin seems to make a more radical claim in relativizing truth not so much to a community but to a kind of cognitive structure. Unwin's position seems more akin to Kant's transcendental idealism-at least to the strain of that elusive doctrine which is especially prominent in the Transcendental Aesthetic, according to which all our knowledge can only be about the world as it appears to creatures with our distinctive human forms of sensibility.4 However, although he accepts 'the mind-contribution thesis'-that