As for rationale, it drew on two kinds of source, divine and social. Around the sixth century B.C.E., Pythagoreans taught that we mortals are on sentry duty and bound to stay at our watch until relieved, an image that clearly implied man's obligation to superior powers, sovereign beyond death. The image would be absorbed by Plato and his innumerable readers, who in the later Roman Empire included Neoplatonists and Christians, both of whom used it, with other borrowings, to fortify their faintly equivocal traditions. For the Christian tradition had until then itself been uncertain. In the Bible, keen eyesight is needed to find suicide expressly forbidden (as perhaps in Gen. 9:5 or Exod. 20:13). And although most suicides in the Bible—Judas the most notorious—are manifest villains, a "suicide guerilla" had slipped in among biblical heroes around the tenth century B.C.E., in the person of Samson (Judg. 16:18–30), and was joined around 70 B.C.E. by another hero, Razias, who had killed himself after military defeat, in the Roman manner (2 Macc. 14:43–46). The early church furthermore revered as saints certain women who had killed themselves to avoid rape. In the fourth century C.E., Christian opinion formers set about closing these loopholes, notably Pachomius (in respect of burial ritual) and Augustine (in argument). A few centuries later, Muslim commentators would do the same for the Koran, whose deficiencies in this particular were amply supplied by the Hadith (tradition).
A second main source for an antisuicide rationale was social. Aristotle had explained the Athenians' mutilation of suicides' corpses on the ground that a suicide had injured his polis (an argument to be seized on gratefully by Christian theologians in the later Middle Ages, when Aristotle became available in Latin). The Jews, for their part, told sympathetically (in Tobit, c. 200 B.C.E.) of a woman restrained from suicide by the thought that it would hurt her father. Even suicide-prone Roman Stoics could be restrained by consideration for their friends. Illiterates meanwhile expressed their social feelings on the subject by ideas about pollution of the community cemetery and bad weather. Finally, social considerations could express themselves on the vertical plane, from master to dependent. A Roman slave who killed himself robbed his owner, who might make him an example by maltreating the corpse. In early medieval Europe—when nearly everyone was someone else's dependent—lords would punish an underling's suicide by confiscating the property. That prerogative gradually passed to monarchs. That suicide was in England classed as a felony until 1961 probably owed its origin to the defiance it had represented, in the early Middle Ages, to the king qua lord.