“The ‘purposive’ man,” Keynes wrote, “is always trying to secure a spurious and delusive immortality for his actions by pushing his interests in them forward into time. He does not love his cat, but his cat’s kittens; nor in truth the kittens, but only the kittens’ kittens, and so on forward forever to the end of cat-dom. For him, jam is not jam unless it is a case of jam tomorrow and never jam today.