Why 'arbitrium' should not be used?

by JLS
for the GC

When Kant says 'arbitrium brutum', he was confused. How can animal choice not be free? (Kant opposes 'arbitrium brutum' to 'liberum arbitrium'.

But "arbĭter" is already a slightly confused notion in Latin, and 'electio' should be best used for 'choice'.

arbiter comes from ar = ad (v. ad init.) and bito = eo, orig.,

"one that goes to something in order to see or hear it; hence, a spectator, beholder, hearer, an eye-witness, a witness (class. through all periods; used several times by Plaut., but only twice by Ter.; syn.: testis, speculator, conscius)."

and so on.