Augustine was one of the first Christian ancient Latin authors with a very clear vision of theological anthropology. He saw the human being as a perfect unity of two substances: soul and body. In his late treatise On Care to Be Had for the Dead, section 5 (420 AD) he exhorted to respect the body on the grounds that it belonged to the very nature of the human person. Augustine's favourite figure to describe body-soul unity is marriage: caro tua, coniunx tua - your body is your wife.  Initially, the two elements were in perfect harmony. After the fall of humanity they are now experiencing dramatic combat between one another. They are two categorically different things. The body is a three-dimensional object composed of the four elements, whereas the soul has no spatial dimensions. Soul is a kind of substance, participating in reason, fit for ruling the body.  Augustine was not preoccupied, as Plato and Descartes were, with going too much into details in efforts to explain the metaphysics of the soul-body union. It sufficed for him to admit that they are metaphysically distinct: to be a human is to be a composite of soul and body, and the soul is superior to the body. The latter statement is grounded in his hierarchical classification of things into those that merely exist, those that exist and live, and those that exist, live, and have intelligence or reason.  Like other Church Fathers such as Athenagoras, Tertullian, Clement of Alexandria and Basil of Caesarea, Augustine "vigorously condemned the practice of induced abortion", and although he disapproved of an abortion during any stage of pregnancy, he made a distinction between early abortions and later ones. He acknowledged the distinction between "formed" and "unformed" fetuses mentioned in the Septuagint translation of Exodus 21:22-23, which is considered as wrong translation of the word "harm" from the original Hebrew text as "form" in the Greek Septuagint and based in Aristotelian distinction "between the fetus before and after its supposed 'vivification'", and did not classify as murder the abortion of an "unformed" fetus since he thought that it could not be said with certainty that the fetus had already received a soul.  Augustine held that "the timing of the infusion of the soul was a mystery known to God alone". However, he considered procreation as one of the goods of marriage; abortion figured as a means, along with drugs which cause sterility, of frustrating this good. It lay along a continuum which included infanticide as an instance of 'lustful cruelty' or 'cruel lust.' Augustine called the use of means to avoid the birth of a child an 'evil work:' a reference to either abortion or contraception or both."

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Augustine was one of the first Christian ancient Latin authors with a very clear vision of theological anthropology.