Changes

::::Coitus interruptus is a non-abortive method of contraception which has always been universally available (see Onan, and interpretations of this passage by Clement of Alexandria and Jerome). There are a number of references to natural family planning prior to the 20th century, although few, if any, entailed an accurate understanding of the periods of maximum and minimal minimum fertility within the menstrual cycle. Soranus of Ephesus (1st-2nd centuries AD) published an extant four-volume treatise on Gynaecology, in which he stated that the time "directly before and after menstruation" was the most fertile period for a woman (which is coincidentally the period of minimal minimum fertility within a typical 28-day cycle.) Augustine of Hippo (and apparently the Manicheans with whom he associated earlier in his life) was familiar with Soranus' work, and writes against the Manicheans: "Is it not you who used to counsel us to observe as much as possible the time when a woman, after her purification, is most likely to conceive, and to abstain from cohabitation at that time, lest the soul should be entangled in flesh? This proves that you approve of having a wife, not for the procreation of children, but for the gratification of passion." (http://www.ccel.org/ccel/schaff/npnf104.iv.v.xx.html).