Natural Law

Aristotle:

'That which is natural is unchangable, and has the same power everywhere, just as fire burns here and in Persia'

For humans, the final of the 4 causes is Eudaimonia - a contented state of being happy and prosperous: we should seek well being and happiness.

Thomas Aquinas:

Influenced by Aristotle, but was religious. He believed that efficient cause of humans and the universe was God the creator. When an object achieves its purpose (telos), it achieves perfection as God intended it to be. Human's final cause is Heaven in the presence of God.

As humans, we begin to perfect ourselves in this life, but fulfil our natures and desires in the next life. Using reason to reflect on human nature we discover our telos. 

Aquinas believed God instilled laws into the world:

• Human law: the law of nations 
• Natural law: moral law built into humans by God. A reflection of the eternal law of God, though we simply need reason to understand human nature
  
• Divine law:  the bible, reflects the eternal laws of God, includes the 10 commandments and the Sermon on the Mount. Can only be seen by people who believe in God
• Eternal law: the principles by which God made and controls the universe, which only God knows completely

Aquinas says God instilled inclinations in us to behave a certain way which leads us to perfection. We should achieve good and avoid evil. This is synderesis - like a moral compass. 

Natural law as an ethical theory:

• an absolute theory
• rooted in the application of human nature
• nature interpreted by reason
• not a fixed law, flexible in application
• humans have a God-given rational nature 
• even without knowledge of God, we have reason 
• universal and unchanging 
• used to judge societal laws
• deontological theory of ethics 

Apparent good: mistaken good, it seems to be good but reason goes against God and perfect human ideals. We mistakenly do evil acts, mistaking them for good ones

Real good: absolute, and always right. Finding our way to perfection.

Aquinas believed there were primary precepts, things that are always true and apply to all and a direct reflection of eternal law, and secondary precepts can be derived from this. They are the fundamental principles of natural law:  (secondary)

• the preservation of life (don't have an abortion)
• reproduction (no use of contraception)
• the nurture and education of the young (everyone has a right to education)
• living peacefully in society (obey the law)
• to worship God (do not worship false idols)

Prudence is the central role of practical reason in determining what is right and proper to do in each situation. NL has to be understood situationally.

The Doctrine of Double Effect:

It is wrong to do a wrong act intentionally, but to do a wrong act with the intention of a good outcome is sometimes the right thing to do. Eg in Euthanasia - giving a terminally ill patient pain killers with the intention of relieving…