In the earliest written sources, abortion is not considered as a general category of crime. Rather, specific kinds of abortion are prohibited, for various social and political reasons. In the earliest texts, it can be difficult to discern to what extent a particular religious injunction held force as secular law. In later texts, the rationale for abortion laws may be sought in a wide variety of fields including philosophy, religion, and jurisprudence. These rationales were not always included in the wording of the actual laws.
Ancient sources
Tribal people in more modern times have been had access to many herbal abortifacients, emmenagogues, and contraceptives, which had varying degrees of effectiveness. Some of these are mentioned in the earliest literature of the ancient world, however citations for abortion related matters are scarce in the earliest written texts.
Social considerations
In the ancient world, discussions of offspring limitation, whether through contraception, abortion, or infanticide, were often linked with discussions about population control, the property rights of the patriarch, and the regulation of women engaged in illicit sex. Cicero explains:"I remember a case which occurred when I was in Asia: how a certain woman of Miletus, who had accepted a bribe from the alternative heirs and procured her own abortion by drugs, was condemned to death: and rightly, for she had cheated the father of his hopes, his name of continuity, his family of its support, his house of an heir, and the Republic of a citizen-to-be."
Families wealthy or poor may have had different reasons for practicing offspring limitation. The wealthy may have been concerned about breaking a large inheritance into numerous smaller portions for many heirs. A poor family may have been unable to feed a large number of children.
Aristotle held positions which align with modern eugenics arguments. In his view, abortion and infanticide were permissible when they accorded with the welfare of the state. He advocated mandatory exposure of children born with deformities, and deemed abortion advisable when a couple had exceeded their quota of children, or when a couple had conceived passed their optimal childbearing age, as he believed that the eudaimonia of the individual was entwined with the welfare of the state. Plato held views similar to Aristotle's.
In Hindu scriptures, the matter is interpreted as reflecting a concern for the preservation of the male seed of the three "pure" castes, with the meaning of one word associated with abortion, bhrūṇahan, being "the killer of a learned Brahmin". Offspring limitation facilitated the financial stability of the influential families, preserving social order, and the males of these castes were required to perform important religious rituals. While caste mixing was severely condemned, abortion was not recommended, and the texts elaborated a complex set of rules for the social integration of people born of such unions.
Of some concern in all these discussions is the ability of the woman to conceal her pregnancy in the early stages, and to terminate an unwanted pregnancy through the use of herbs or, more rarely, crude surgery. Since menses may be interrupted by medical conditions other than pregnancy, a woman taking an emmenagogue could not necessarily be accused of attempting abortion, even if she did lose a fetus with the bringing on of stopped menses. Therefore, social control of childbirth, essential to the preservation of the social order, could only effectively be exercised after quickening.