 The examples reveal a distinction that structures much of the discussion for the next ten chapters. For it looks as if ‘factual’ inquiries concern whether some attribute belongs to some subject (movement to the earth, eclipse to the moon), and the search for the reason why will be a search for the causal explanation of the attribute belonging to that subject. By contrast, it looks like the move from ‘if’ to ‘what’ is a move from establishing the existence of some subject (‘god’, ‘man’) to establishing what it is.