Natural Law by Thomas Aquinas: an Examination

Explain Aquinas’ Natural Law theory

Thomas Aquinas was a 13th century monk who studied Aristotle’s philosophy. He developed his Natural Law from these studies. Natural law is an absolute, deontological theory which states that morals are issued by God to nature. It includes 5 primary precepts of which Aquinas believed were the basis of living a moral life. The Natural Law, as applied to the case of human beings, requires greater precision because of the fact that we have reason and free will. It is the of nature humans to act freely (i.e. to be provident for ourselves and others) by being inclined toward our proper acts and end. That is, we human beings must exercise our natural reason to discover what is best for us in order to achieve the end to which their nature inclines. Furthermore, we must exercise our freedom, by choosing what reason determines to naturally suit to us, i.e. what is best for our nature.

Aquinas looked particularly at Aristotle’s theory about the final cause and prime mover. The final cause being the purpose of everything and the prime mover, the thing that is pushing everything towards its final cause. From this he made 5 assumptions: Everything in nature has a purpose; God created all nature; failure to develop nature to do its purpose is an imperfection; God’s moral laws can be known through reasoning; and natural law is part of God’s divine plan. To summarise, there are certain laws of nature that we should follow in order to become perfect and reach our purpose/final cause.

The primary precepts are as follows: preservation of life, living in an ordered society, worshipping God, education and reproduction. According to Aquinas, our actions must always conform to these precepts. For example, abortion, suicide and murder are all wrong because they all go again the precept of preserving life. Whereas attending church every Sunday is something Aquinas thought we should do because it is a secondary precept of the first, worshipping God.

One more relative concept of Natural Law however, is that it can be more flexible. It recognises that all individual situations are different and we must consider this when making moral judgements. In some situations, the doctrine of double effect can be used. One example would be if a pregnant woman has cancer and the only way to save her would be for the doctor to perform a hysterectomy. This would kill the unborn child but save the mother, rather than them both dying. Natural Law says that it would be acceptable for the doctor to perform the hysterectomy because the act in itself is not wrong and the intentions of the doctor are not evil. The death of the unborn child is an unintended side effect.

To conclude, Natural Law is a deontological absolute theory that states that we should all follow the 5 primary precepts. Acts that follow the primary precepts are secondary precepts. However in some cases the doctrine of double effect can be used to justify an action which has bad consequences.

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