Truth, pragmatic theory of

1. Pragmaticism

C.S. Peirce believed that any two minds investigating a given question would tend eventually to arrive at the same answer, even if they used different methods and different pools of evidence: ‘Let any human being have enough information and exert enough thought upon any question, and the result will be that he will arrive at a certain definite conclusion, which is the same that any other mind will reach’ (Peirce 1931–58 (7): 319). Moreover, this one answer that all would reach is, by definition, the true answer: ‘The opinion which is fated to be ultimately agreed to by all who investigate is what we mean by truth’ (Peirce 1931–58 (5): 407). Indeed, in principle, consensus embodies the truth no matter what method was used to bring about the consensus. ‘If a general belief…can in any way be produced, though it be by the faggot and the rack, to talk of error in such belief is utterly absurd’ (Peirce 1931–58 (8): 16). Although Peirce thought that in the long run the only method which could produce and sustain a consensus agreement is what he called ‘abduction’ (what is now called ‘inference to the best explanation’), it is important to remember that he did not think propositions which would be universally accepted are true because they were arrived at by abduction; rather, he thought they are true just because they would be universally accepted (see Peirce, C.S. §3).

Whence Peirce’s confidence that investigators would move towards a common conclusion? Ultimately, our evidence takes the form of perceptions, and these perceptions are controlled by a single fixed reality which is public to all. Since there is just one objective reality and it is driving all of us to beliefs that accurately reflect it, we are driven to agree with one another. So, in the long run, the only propositions with which everyone would agree are those that accurately reflect reality. Hence, ‘is true’ is equivalent to ‘accurately reflects reality’. It might seem odd, then, that Peirce turns his attention away from this equivalence and focuses instead on what would otherwise seem to be an incidental equivalence between ‘is true’ and ‘would eventually be agreed to by everyone with sufficient relevant experiences’. But for Peirce it is the former relation which is the trivial one because reality, he thought, is just a construct of the community of human minds. Specifically, what is real is just whatever we would come to agree is real: ‘the real is the idea in which the community ultimately settles down’ (Peirce 1931–58 (6): 610) and ‘everything, therefore which will be thought to exist in the final opinion is real, and nothing else’ (Peirce 1931–58 (8): 12). Peirce called this his ‘social theory of reality’.

But notice now how this ontological doctrine undermines Peirce’s own explanation for why all who investigate a given question would ultimately come to agreement: on a realist ontology, the notion of reality controlling our perceptions is based on common sense; but on the social theory of reality, it is an idea in the minds of those who have already reached the final opinion which is causing those who have not reached it to have certain perceptions. Indeed, matters are even stranger than this; for the very perceptions that caused those who have reached the final conclusion to reach it were forced on them, in a reverse-chronological direction, by the final conclusion which, at the time they had the perceptions, they had not reached. Therefore, some of the perceptions you and I are having right now are forced on us by an idea which, if we have it at all, we will only have at some future time. Peirce himself was aware of this rather fantastic implication of his views and attempted to defend it:

At first sight it seems no doubt a paradoxical statement that, ‘The object of final belief which exists only in consequence of the belief, should itself produce the belief’;…there is:

But this will not do. On the analysis of causation which Peirce is assuming, the relation between gravity and the tendency of things to fall is one of identity, not of mutual causation. Moreover, even if we allow that gravity is in some sense a consequence of the fact that things tend to fall, neither gravity nor the tendency are events in time. Hence, to assert that the former is both a cause and a consequence of the latter is not to assert the possibility of reverse-chronological causation. But coming to believe the final conclusion, and the occurrence of the perceptions that bring about that belief, are both events in time, and they come at different times. Hence, to assert that the chronologically earlier of these is caused by the chronologically later is to assert something not at all analogous to any causal relations involving the inkstand.

The problems in Peirce’s account go even deeper. Although Peirce sometimes speaks as if the final conclusion is fated or destined, on those occasions on which he self-consciously considers whether this conclusion will ever actually be reached, he is much more cautious: ‘We cannot be quite sure the community will ever settle down to an unalterable conclusion upon any given question…nor can we rationally presume any overwhelming consensus of opinion will be reached upon every question’ (Peirce 1931–58 (6): 610).

So the causal action of the final conclusion on our present actual perceptions is not only reverse-chronological, it is also action from within a hypothetical domain to the actual domain.