Volume 8/9, 1996
Rationality II & III
Ralf Naumann
Pages 111-148
Internal Realism, Rationality and Dynamic Semantics
Putnam’s internal realism implies a form of conceptual relativity with respect to ontology. There can be different descriptions of the world which are based on distinct ontologies. It has been argued that this relativity forecloses any possibility of unifying our knowledge and can even lead to inconsistency. If this is true, internal realism should be abandoned because it is compatible with non-rational positions. We will argue that these objections can be dismissed if truth as idealized warranted assertibility is understood as stability of a belief state under new evidence. This view of truth is still compatible with the existence of distinct belief states expressing different views on the world. This understanding of the notion of truth is a consequence of interpreting both our cognitive activities and the notion of meaning dynamically. The meaning of a sentence is no longer given in terms of (static) truth conditions but as a relation between belief sets, that is, as a kind of information change potential.