According to the Rule, some may not become monks: one who has murdered an Arahant (Enlightened Being), one who has murdered his mother or father, one who has injured the Lord Buddha, one who has raped a Buddhist nun, one who has caused a schism in the Sangha, one who has pretended to be a monk without ordination, one who has left the Sangha and ordained in another religion, one who as a monk committed any of the four 'disrobing offences' (see below), one who is a Eunuch, Hermaphrodite or who is an animal ...