ABSTRACT
Validity alone does not ensure that arguments are sound. A sound argument must also be based on acceptable premises. However, in certain circumstances, it is legitimate and worthwhile to suspend the ‘acceptability’ requirement. Sometimes reasoning is based on claims for which no defence is offered. We refer to such claims as assumptions. Following Lemmon:
By an assumption, we shall understand a proposition which is, in a given stretch of argumentation, the conclusion of no step of reasoning, but which is rather taken for granted at the outset of the total argument.
