Counterfactual conditionals

‘If bats were deaf, they would hunt during the day.’ What you have just read is called a ‘counterfactual’ conditional; it is an ‘If…then…’ statement the components of which are ‘counter to fact’, in this case counter to the fact that bats hear well and sleep during the day. Among the analyses proposed for such statements, two have been especially prominent. According to the first, a counterfactual asserts that there is a sound argument from the antecedent (‘bats are deaf’) to the consequent (‘bats hunt during the day’). The argument uses certain implicit background conditions and laws of nature as additional premises. A variant of this analysis says that a counterfactual is itself a condensed version of such an argument. The analysis is called ‘metalinguistic’ because of its reference to linguistic items such as premises and arguments. The second analysis refers instead to possible worlds. (One may think of possible worlds as ways things might have gone.) This analysis says that the example is true just in case bats hunt during the day in the closest possible world(s) where they are deaf