Abstract

Arguers sometimes cite a decision made in an earlier situation as a reason for making the equivalent decision in a later situation. I argue that there are two kinds of “case-to-case arguments”. First, there are arguments by precedent, which cite the mere existence of the past decision as a reason to decide in the same way again now, independent of the past decision’s merits. Second, there are case-to-case arguments from parralel reasoning which presuppose that the past decision was justified and are used to show that an equivalent present decision would also be justified. Both arguments are a type of argument by analogy. They differ in their structures and conditions of cogency, even though they often look the same in presentation. Their similar appearance poses a risk of miss-evaluation and fallacious use. Therefore a clearly theorized distinction is important.