 Audrey’s winning the race is a sufficient condition for us having a celebration, and her winning the race is the reason why we will be celebrating. Our celebration, however, is not likely to be the reason why she wins the race. In what sense then is the celebration a necessary condition of her winning the race? Again, there is a ground for inferring: that we don’t celebrate is a ground for inferring that Audrey didn’t win the race. English time reference appears sensitive to the asymmetry uncovered here, in the way noted in the previous section. The natural way of writing the contrapositive of (ix) is not the literal “If we will not celebrate, then Audrey does not win the race”, but rather something like: