Abstract

Logical deduction is central to analytic philosophy: most crucially, it provides the standard against which we judge arguments. Traditionally, the relation of deducibility between propositions, i.e. whether or not a conclusion logically follows from a set of premises and rules of inference, is said to be knowable a priori and with absolute certainty. It is often taken to be self-evident that if you accept the premises of a valid argument, the conclusion necessarily follows. By making use of a theory known as ‘meaning finitism’ David Bloor challenges this traditional account of logical necessity, arguing that ‘what, in the realm of language and ideas, we refer to as logical relations, and logical constraints, are really the constraints imposed on us by other people. Logical necessity is a moral and social relation’.

In this essay, I will examine whether Bloor is justified in making such a bold claim. I will begin by giving an account of what is meant by terms such as ‘logic’ and ‘logical necessity’. I will then outline two different interpretations of Bloor’s thesis: the first being the ‘external’ or ‘holist’ interpretation under which the choice to accept or not accept a given logical system is a contingent and social matter. This first interpretation would take Bloor to be advocating for logical pluralism or relativism. On the second or ‘internal’ interpretation, social factors penetrate a given logical system itself: the relation between premises and conclusion, given accepted rules of inference, is a moral and social relation. In the remainder of this essay, I will evaluate whether or not Bloor succeeds in justifying either of the above two interpretations.