 One effect of the introduction of language is that people are able to learn the opinions of other people. They will inevitably discover that some people disagree with them, not least in speculations about the nature of the universe. So the art of dialectics or debate (jadal) is introduced in order to resolve differences of opinion between two people. ([Letters] (140,141) 150.2–151.7.) But a dialectical resolution of a disagreement is no guarantee of the truth of the agreed conclusion; one of the debaters might just be better at arguing ([Debate] 40.9–13). 