Classical Christology provides reason to reject the principle of alternative possibilities [PAP]. The Gethsemane prayer highlights an instance in which Jesus Christ performs a voluntary and morally significant action which he could not have done otherwise, namely, Christ’s submission to God’s will. Two classical Christological doctrines undermine PAP: impeccability, and volitional non-contrariety. Classical Christology teaches that Christ could not sin, and that Christ’s human will could not be contrary to his divine will. Yet, classical Christology also teaches that Christ’s death (...) is voluntary and morally praiseworthy. First, I present the relevant elements of classical Christology: dyothelitism, impeccability, and volitional non-contrariety. Second, I define and disambiguate varieties of PAP. Third, I show that Christ’s prayer in Gethsemane disproves PAP. I respond to several objections along the way. Finally, I reflect on the implications of denying PAP. (shrink)