Theoria: An International Journal for Theory, History and Foundations of Science

Volume 18, Issue 2, Mayo 2003

William H. Hanson
Pages 171-177

Logic, the A Priori, and the Empirical

The time-honored view that logic is a non-empirical enterprise is still widely accepted, but it is not always recognized that there are (at least) two distinct ways in which this view can be made precise. One way focuses on the knowledge we can have of logical matters, the other on the nature of the logical consequence relation itself. More specifically; the first way embodies the claim that knowledge of whether the logical consequence relation holds in a particular case is knowledge that can be had a priori (if at all). The second way presupposes a distinction between structural and non-structural properties and relations, and it holds that logical consequence is to be defined exdusively in terms of the former. It is shown that the two ways are not coextensive by giving an example of a logic that is non-empirical in the second way but not in the first.