In addition to a 17th-century Dutch theologian (Petrus van Mastricht) and the King James bible, one of the authorities cited by Alabama chief justice Parker in his ruling on IVF is the medieval theologian Thomas Aquinas. Parker's ruling cites Aquinas six times.
As someone with an M.A. and Ph.D. in historical theology — from a Catholic university — I know a little about Aquinas. Here are some salient points: