The fraction of ''all different'' combinations: Justifying the semi-classical partition function

Modern statistical mechanics directly acknowledges the indistinguishability of identical particles, a characteristically quantum property. Under laboratory conditions such that classical physics ought to suffice for most purposes, the indistinguishability is often incorporated by a judicious division by N!. This paper explores a common justification for that procedure-and finds it wanting. Nonetheless, the procedure is valid, but for a different reason. (C) 1997 American Association of Physics Teachers.