There is no adequate definition of 'fine-tuned for life'

Abstract

In this article a case is mounted for the sceptical position that cosmic fine-tuning does not support an inference to anything extracosmic. To that end three definitions of ‘fine-tuned for life’ are proposed: the ‘slight difference’ definition, the (unconditional) probability definition, and John Leslie’s conditional probability definition. These three definitions are the only ones suggested by the relevant literature on fine-tuning and the anthropic principle. Since on none of them do claims of fine-tuning warrant an inference to something extracosmic, it is concluded that there is no definition of ‘fine-tuned for life’ serving this function.