Fetus Soul

In the 1600s some moral theologians thought that the fetus did not have a soul until a few months after conception.  With a soul the fetus became a human person.  This idea died in 1708 when the church made a feast day, December 8, of the Immaculate Conception.  This was when Mary was conceived without sin and it had to be nine months before her birth, September 8.  Because Mary was a full human being from the moment of her conception, was she able to be endowed with grace that freed her from original sin.  If Mary was a human person with soul from conception, then it was likely that human life began with conception, the theologians reasoned.