Natural Law has roots that stem back to Ancient Greece, and it was Aristotle who really created the approach. It was also depicted in Sophocles’ play Antigone, where the protagonist claims her right to bury her brother despite the King (Creon) ordering that he be fed to dogs. Antigone, (the protagonist) proclaimed this because she believed that there was a higher law than the King’s, particularly, Natural Law. However, it was not until the 13th Century until Thomas Aquinas developed its key features, that it was actually more widely recognised as a moral theory. When we focus on the recipient of the natural law, that is, us human beings, the proposition of Aquinas's natural law theory that comes to the forefront is that the Natural law establishes the basic principles of practical rationality for human beings, and has this status by Nature. These are to be followed universally, as Cicero puts it; it is ‘one eternal and unchangeable law will be valid for all nations and all times’.
According to Aquinas, all humans seek good and when we do wrong or evil, it is only because we are only seeking ‘apparent’ goods and not real goods. So, we could ask ourselves, how does Aquinas define a ‘real’ good? A real good is when the said ‘good’ falls under the five primary precepts. These are: self-preservation and preservation of innocents, educating children, living in society, reproducing and worshipping God.
Aquinas also believed that we can use our rationality to know Natural Law. It is inherent within our human nature, God reveals specific commands but these do not go against natural law but rather, further develop it. Aquinas said that a moral life is a life entirely followed ‘according to reason’.
Aquinas allowed for the Aristotelian insight that the particulars of the situation always outstrip one's rules, so that one will always need the moral and intellectual