Some people may agree and say that natural appeals to the sense we have that morality is more than just a matter of what people’s preferences and inclinations may be. Even though different cultures and individuals may reach different conclusions on the rightness or wrongness of a moral action there’s is a prevailing sense that some things are of intrinsic value.
As well as this natural law focuses on human character and its potential for goodness and flourishing rather than on the rightness or wrongness of an individual’s particular acts. Therefore allowing for some measure of flexibility and also work as a positive motivational tool.
In addition natural Law seeks us, as humans, to push and become the best we can be. We are told to aim for a purpose and maintain an ordered society. Maintaining an ordered society, as well as certain other primary precepts, is a good system for preserving the environment. The theory isn't belittling, and isn't a "single factor theory" like utilitarianism.
Alternatively others may argue that natural law depends on accepting the view that good is what is found in nature. However, they may ask ‘Is everything found in nature good?’ Are cancerous tumours good? If their goodness consists in fulfilling the functions of a cancerous tumour, those who experience then at first hand would be hard pushed to agree.
Furthermore natural law could result in poor outcomes if the primary precepts are rigidly clung to. In terms of sexual ethics, Natural Law would rule out contraception - the removal of contraception in many strictly religious countries has already led to more and more cases of AIDS across the globe.
Moreover the theory is arguably based on outdated social norms and is not relevant to modern society. In terms of sexual ethics, it is not socially acceptable to suggest that homosexuality is immoral. Furthermore, society has moved on since Aquinas's time; sex for pleasure is