Outline the main threads of thought in Preformatism.

Preformatism is the supposed existence of all the parts of an organism in rudimentary form in the egg or the seed and is inferred in the early writings of the Christian Church fathers. They made no developmental distinctions and that as the unborn child is a creation of God, to kill it (by taking drugs) was murder and this implied what we call today "personhood". This view was soon eclipsed by the teachings of Augustine in the early 5th Century AD. Since the anti-liberal "Leonine" reforms of the Leo XII 1889s, it is once again accepted by the Catholic Church.