The chapter is concerned with a commitment of the logical pluralist: if there are at least two correct logics, then these logics will either involve different logical vocabulary or they will assign different meanings to the shared vocabulary. A central question is how this plurality in meaning can be implemented within a pluralist framework. Pluralists typically endorse claims to the effect that (i) the connectives of the logics have different meanings or (ii) that the notion of validity employed by one logic may be relevantly different from the one employed by the other. A further important question is whether the plurality of meanings is confined to the theoretical level only or whether a corresponding plurality is postulated regarding the extra-systematic counterparts of the logical vocabulary of correct logics. I argue that both connectives pluralism and consequence pluralism are implausible when construed as pluralistic theories. Meta-contextualism–the view that the question of whether the meaning of the logical terminology is the same or different in different contexts is itself subject to semantic variability–is shown to have exceedingly radical implications.

This chapter explores three dimensions on which logical plurality may arise. The first is concerned with the application of logic. Traditionally, logic was taken to be universally applicable in the sense that a deductively valid argument can be applied in any discourse or inquiry whatsoever. Some pluralists oppose that view by arguing that there are arguments which, though deductively valid, cannot be applied across the board. Deductive validity, on that view, is domain-dependent. The second dimension concerns semantics. Typically, if logics differ in their logical vocabulary, then they will draw the line between valid and invalid arguments in different ways. Even if the logical vocabulary of two logics is superficially the same, the sets of arguments the logics classify as valid may differ due to differences in the meaning of the logical vocabulary. The third dimension concerns the nature of validity. The most substantial kind of pluralism amounts to claiming that there is more than one extra-systematic relation that qualifies as a relation of logical consequence. The chapter outlines both the pluralist and the monist positions on those dimensions and identifies some core commitments.