Hume's fourth premise of the teleological argument questions which assumption?

Hume's fourth premise of the teleological argument indeed questions the assumption that complexity implies a complex designer. This premise critically examines the leap in reasoning that concludes from observing complexity in the world to inferring the existence of a designer who must be equally complex. Hume suggests that while we might observe complex structures in nature, it does not necessarily follow that such complexity must originate from a designer whose own complexity matches or exceeds that of the structures in question.

In essence, Hume points out that complexity alone does not serve as definitive evidence for the existence of a designer, as it raises further questions about the nature and origin of both complexity in the universe and the designer themselves. By challenging this assumption, Hume encourages careful scrutiny of the relationships we draw between cause and effect in nature and the inferences we make about existence based on those observations. This philosophical inquiry is central to his skepticism regarding the teleological argument's conclusions.