Closed systems, explanations, and the cosmological argument

Examples involving infinite suspended chains or infinite trains are sometimes used to defend perceived weaknesses in traditional cosmological arguments. In this article, we distinguish two versions of the cosmological argument, suggest that such examples can only be relevant if it is one specific type of cosmological argument that is being considered, and then criticize the use of such examples in this particular type of cosmological argument. Our criticism revolves around a discussion of what it means to call a system closed, and what it means to call an explanation complete. Our analysis makes no suppositions about the nature of the infinite, and is therefore independent of many of the issues around which contemporary discussions of the cosmological argument have tended to revolve.