§408. Uses of the Ablative As Instrumental

Means, Instrument, Manner, and Accompaniment are denoted by the Instrumental Ablative (see § 398), but some of these uses more commonly require a preposition. As they all come from one source (the old Instrumental Case) no sharp line can be drawn between them, and indeed the Romans themselves can hardly have thought of any distinction. Thus, in omnibus precibus ōrābant, they entreated with every [kind of] prayer, the ablative, properly that of means, cannot be distinguished from that of manner.

Ablative of Means or Instrument