Kant’s moral argument began with him arguing that a moral action is about doing one’s duty. Kant focus’ on how people feel obliged to do good, knowing that it will bring about more good and overall more happiness, this search for the higher good is referred to as the Summum Bonum. Kant also states that for his theory to work then there must be universal moral law that a person must find through use of reason. Once this universal moral law is found then a person will feel a duty to follow it. According to Kant the reason to do one’s duty is to achieve the Summum Bonum. He argues that we could not be happy without being morally good people, because being morally good is part of nature of human happiness.
Possibly the most important point of Kant’s moral argument is his acceptance that being morally good, and doing your duty does not always lead to happiness. Kant says people should do their duty because it is the right thing to do. Happiness may result from doing the right thing, but he believes it is never reason for doing morally good actions. Kant is well aware that doing your duty doesn’t sound as rewarding if ultimately it doesn’t lead to the Summum Bonum. He believes that through reason we can work out what the right thing to do is; this is because the right thing to do has to be applicable universally. Your moral duty is to do good intrinsically, the consequences of doing your duty is not a motive for doing a morally good action.
Kant believes that the highest good must be achievable; otherwise moral goodness would ultimately be pointless. Even though the Summum Bonum cannot be guaranteed in the world by doing your duty, Kant believes that God’s existence is the guarantee that moral virtue and the Summum Bonum are achievable. The idea of God’s existence as a matter of reason must be postulated, as only he can make the greatest good achievable. Kant believed that we must have a duty to achieve the Summum Bonum and because it was not achievable in this lifetime, we must be able to achieve it in the next.
In conclusion, Kant doesn’t see his moral argument as a proof that God exists, but he believes that in order for moral behaviour of human beings to make sense, we must postulate three things. The three postulates of morality are; free will, immortality and the existence of God. He believed an action is only truly moral if we chose it freely through our own choice. He also argues that acting according to our moral autonomy should result in happiness as demanded by justice. As this doesn’t happen, there must be life after death. The final part of the conclusion of Kant’s moral argument is that God must exist as a postulate of practical reason. Without the existence of God we cannot have the afterlife and we would not be able to fulfil our obligation of reaching the Summum Bonum.
