Final answer:
Natural law theory is the idea that moral principles are inherent in the natural order, and human reason can discover them. Significant challenges arise from varying interpretations of 'nature' and difficulty in deriving fixed moral principles solely from human nature. Natural law theory focuses on universal morals and is not predicated on subjective behaviors or natural acts.
Step-by-step explanation:
Natural law theory proposes that there are inherent moral principles in the natural order that human reason can discover. According to this view, what is consistent with natural law is right, and what is not in keeping with natural law is wrong. The focus of natural law is on the universal moral laws rather than simply on natural acts or behaviors. It is important to understand that an action being 'natural' does not automatically make it morally correct.
However, one significant challenge to natural law theory is the variability in how 'nature' is interpreted by different people. For example, while traditional natural law theory highlights positive human traits such as the desire for knowledge and goodness, other philosophers may view humans as essentially selfish. Consequently, if a human trait such as aggression is considered natural, it raises the question of whether aggressive acts, like fighting or warfare, are morally justifiable.
Philosophers like Thomas Aquinas contributed to the classical natural law approach, emphasizing that human laws must align with natural law for societal governance and that nature is not subjective. Aquinas also indicated that while natural laws can be known through reason, divine laws need to be revealed by God for humans to reach salvation. Moreover, this theory does not necessarily rely on the existence of God; for instance, Aristotle viewed the order in nature without attributing it to divine intervention.
Despite these foundations, challenges arise from the fact that humans exhibit diverse behaviors influenced by their environment. Critics argue that it is therefore difficult to derive solid moral principles based solely on human nature or biological facts. Additionally, ethical naturalism, which relates closely to natural law theory, posits that what is 'good' is what naturally leads to human flourishing, and that what is 'bad' is that which distorts our nature.