Natural Law Theorists, like St. Thomas Aquinas, claim that law should be necessarily bound to morality and should serve the common good. They also claim that any law that is not partial to the common good is not a law at all. By judging a current system of Positive Law using Natural Law Theory, one might find the Natural Theory to no longer be relevant.
I believe Aquinas’ main purpose in his discourse on natural law was to provide adequate reasoning as to why one should follow Judeo-Christian morals and why the law should be framed under such light. In the age of Aquinas, social reform was necessary but, over time, as nations have developed, morality has become more in tact. Though, many still argue that there are many places in the world where people are being denied basic civil liberties. In these places, where basic universal morals have yet to be met, I do believe that natural law is still relevant. In more developed and socially liberal countries like the USA, what is beneficial to the common good, is no longer bound to an inherent morality, thus suggesting that the concept of Natural Law has become obsolete.
Today, we in the USA have positive laws that do benefit the common good and would be defined as amoral by the Natural Law Theorists. Take for example the legal use of contraception and abortions. Any traditional moralist would adamantly oppose the use of such and would claim that humans should only have sex to procreate. But, it is really feasible to keep human’s from doing what they want in their own home? Is it not stripping of freedom to be denied the most natural pleasure? Thirdly, is society not better off than not when it is able to keep low birth rates and avoid unwanted pregnancies- for the implications of the opposites are quite detrimental to families, individuals and society as a whole. With this example, we see it is possible to benefit the common good and not adhere to Natural Law Theory.
Furthermore, Aquinas himself admits that natural law develops differently in different places, therefore there is no necessary common good behind natural law. Depending on their origin, opposing belief systems will develop different systems, maxims and ethics. So, what is natural and ethical for some might not be for others. An attempt to mediate these differences would be quite inefficient. For a country like the USA to adopt a Natural Law Theory would by no means be in favor of the common good, because the common good is not that easily agreeable.
My main concern with Natural Law Theorists is their failure to realize that the world, society and morals are constantly changing entities. Christian values were once a very vehement force in creating a stable and just society but there becomes a point where this code of morals should no longer be a necessary force. In conclusion, I find that Natural Law Theory aims at an ideal that might have been relevant ages ago, but as society has developed, its end goal has grown less and less imposing. It has become anachronistic.