Augustine specifies in [Contra Julianum opus imperfectum 5.15.52] that the body of Mary although it came from this [concupiscence], nevertheless did not transmit it for she did not conceive in this way. Lastly, De Genesi ad litteram 10.18.32 asserts: And what more undefiled than the womb of the Virgin, whose flesh, although it came from procreation tainted by sin, nevertheless did not conceive from that source.
Both Thomas Aquinas and Bernard of Clairvaux rejected the immaculate conception. The Franciscans (who affirmed the doctrine) and the Dominicans (who denied it, and of whom Aquinas was one) argued bitterly over whether this doctrine should be accepted, with the result that the pope at the time had to rule that both options were acceptable and neither side could accuse the other of heresy (ironic that several centuries later, denying this doctrine now results in an anathema from Rome). http://aristophrenium.com/fisher/was-mary-sinless/
Correct. My intent was to show that the early Church had developed Mariology which was in response to your request for information. Please refer to my reply to Old Reggie on post 1002 for some dates.