Because and although: a case of duality?

König (1989) argues that there is a relation of duality between concessive and causal constructions. Therefore, he maintains, any account of the meaning of causal connectives like because, via duality, also provides an account of the meaning of concessive connectives such as although. This paper lists a number of problems with König's account. Appealing to notions central to relevance theory, it will be argued that context plays an important role in determining the propositions expressed by utterances of causal and concessive sentences. Because of this context-dependence there cannot be said to be a semantic relation of duality between because and although.