There are two different ways to apply the distinction between dialectical and demonstrative argument, and it’s important to be aware of the difference. I draw the terms dialectical and demonstrative argument from Alasdair MacIntyre in Three Rival Versions of Moral Inquiry (pages 88-9), who in turn takes the distinction from Boethius‘s De topicis differentiis and ultimately from Aristotle’s Topics. The key point is that dialectical argument argues to first principles, and demonstrative argument from first principles.

But what are those first principles? Are they first principles for knowledge in general, or merely first principles within a single paradigm? Continue reading →