An explanation of Kant's moral argument (25)
Kant’s moral argument focuses on the notion that God must exist to provide structure to the moral universe. Technically he did not believe that is was possible to prove the existence of God through rational or empirical means. It is important to outline two key ideas before explaining the details of the moral argument. These ideas centre around his assumptions of the universe: that the universe was fair; and that the world around us is fundamentally rational. He begins with the unspoken assumption that the world is fair, owing to the dominance of the enlightenment belief that the universe was fundamentally knowable through reason. It is important to note that Kant began a new way of looking at knowledge. He believed that we could know the world through reason in an ‘a priori synthetic’ way. This was a complete change from how the world had been view previously and was known as Kant’s Copernican revolution. In essence Kant believed in two separate worlds of knowledge: noumenal and the phenomenal worlds. The noumenal world is the world as it truly is without being observed. It is fundamentally unknowable because the act of observation changes the very thing that we observe. It is as though human beings have a specific set of spectacles that cannot be taken off and like the proverbial rose tinted ones they change our perception of the world around us. This personalised view of the universe is the phenomenal world. However, what is key to explaining Kant’s moral argument is the fact that reason is the tool that can be used to know the true nature of the universe as it does not and cannot change.

Kant’s moral argument focuses on reason, good will, duty and the notion that we ought to strive towards moral perfection. It begins with the claim of two things that have him in awe: the starry heavens above; and the moral law within. This moral law for Kant was universal and objective. An example of this might be seen in the wide scale agreement that murder or torture is wrong. There seems to be agreement across cultures that certain actions are intrinsically wrong. This, for Kant, suggests that there is a universal objective moral law. He believed that the highest form of goodness was the notion of good will, namely that someone would freely choose to do good for no reward whatsoever, only for the sake of goodness. Moreover, Kant believed that we have a moral duty to do such good things. He would argue that we have an awareness of what is right and wrong and that good will should make us act accordingly as reason dictates this to be the case. In a way it doesn’t make any rational sense to act in an immoral way. If I were to act out of nepotism (favouritism) or from emotion then I could never discern the universal objective moral law as these factors would cause me to change my opinion of what was right or wrong depending on how I was feeling or what the circumstances happened to be. So I must choose the good based on good will and reason. Duty was seen by Kant as a way of fulfilling this end without being misguided by emotion or factors of personal gain. It is here that we come to a key point in Kant’s argument, namely the notion of ‘ought’ implies ‘can’. He believed that we can only have a duty to do some thing that we can do. For example, I cannot have a duty to fly unaided as it is not something that I can do; or if I were to come across someone drowning in a lake but could not swim Kant would suggest that I would not have a duty to jump in and save them. My duty in the latter case would be to find someone who could swim so I would need to raise the alarm. Once we have this notion of ‘ought’ implies ‘can’ in our mind the argument becomes much clearer. If I can choose to do the good (using reason, good will and duty) in one case then I should be able to do this in every case, moreover that I have a duty to achieve this moral perfection. Kant called this moral perfection the Summum