By Fr. Bud Grant
Last month I tried to show that while Natural Law asserts universal and necessary moral principles, it does not necessarily lead all people to the same specific moral practices. I hope to show how this is not a contradiction.
First, however, we must define “law.” Thomas says that it is “a rule and measure of acts” (ST I.II.90.1). But this isn’t all that helpful, is it? We have, for example, both the “law” of gravity, and the Ten Commandments. Unless we are Harry Potter or John Glenn we have no choice but to obey the former while the latter are rather commonly violated. Nonetheless, all laws are derived from reason, both those which must be obeyed and those which ought to be.
Furthermore, all law is aimed at the common good. This is worth sitting with for a moment. The laws of nature have little regard for individual entities, squandering them profligately (like the tens of thousands of acorns which never become oaks). Yet through the order (rationality) of nature, the whole coheres and perdures over time. In some ways humans are subject to this harsh law, but because we are also endowed with reason we have choices to either advance the common good or to put our own advantage first. This, by the way, explains sin. It is literally a dis-order — choosing a lesser over a greater good.
The source of all law is God. We know God’s law through either faith or reason. What Thomas calls “divine law” is revealed through the Scriptures. Though not irrational, human reason will never be sufficient to know this law without grace. What Thomas called ‘eternal law’ is knowable through human reason. An example of the divine law is the Trinity. No great thinker, on her own, would ever arrive at this notion without the grace of faith. Evolution, on the other hand, does not require revelation, it can be discerned through the use of what Thomas calls “right reason.” This is where it gets exciting: these two fonts of law cannot contradict one another.
The Bible cannot reveal something as true that our human reason discovers to be false because the source of both reason and the revelation is God. If there appears to be a contradiction, then we are simply mistaken. We are either misreading the Scriptures or not reasoning well. Thomas’s extraordinary confidence shines brightly here. We can and ought to be people of both reason and faith. We once believed that the world was created in seven days, misreading Genesis 1 as if it were a science text. When Darwin and others demonstrated irrefutably through reason that this could not have been the case we were forced to re-read that ancient text and rediscover the exquisite theological truth that gets buried in the silly “creationist” debate. Science can tell us when and how creation happened, but only biblical theology can tell us who and why.
Natural law is that portion of the eternal law which we have already come to know. Let me illustrate: prior to Newton, the law of gravity was part of the eternal law, but not the natural law (it was knowable, but not known). Once the apple dropped on his head, the law of gravity became part of the ever expanding sub-set of the eternal law that we call natural law. It is breathtaking to consider how much natural law has expanded since Thomas’ time.
There are two categories of natural law, the primary and the secondary principles. Primary principles apply to all people in all times and situations. They are, in other words, universal and necessary. Secondary principles are derived from the primary, but these are time and place sensitive: different people in different situations will do different things. We’ll examine that paradox next. Before I close, however, a reader asked that I suggest helpful books. Here’s one: “Aristotle’s Children” by Richard Rubenstein.
(Father Bud Grant is an assistant professor of theology at St. Ambrose University in Davenport.)