Ryan v. Biden in Thomist perspective

This is my follow-up to the last redated post.

The difference between Ryan and Biden on abortion is this. For Aquinas, there are four kinds of law: eternal law, divine law, natural law, and human law. Since human law is aimed at human happiness and not salvation, it has to be based on considerations of natural law, not divine law. The claim that the right to life begins at conception, for Biden, is a matter of divine law. It is something that we couldn't discover by ordinary moral reflection apart from the Church's teaching on the matter. So, even though he thinks abortion wrong, he thinks it wrong because the Church teaches that it is wrong, and not because we could discover this on our own. Ryan, on the other hand, not only accept the Church's teaching on abortion, he thinks that human beings reflecting on the matter, could come to the anti-abortion position by natural reason alone. Even though much of our culture denies that abortion is morally wrong, those who do so, by thinking in moral terms, could and should reach the conclusion that abortion is, almost always, homicide without adequate moral justification. As such, he therefore believes it appropriate for government to legislate concerning it.