Like Aristotle, Kant believed that knowledge begins with experience, or what he calls practical reason. Moral principles can be understood by studying human experience: reality can tell us how things ought to be. Like Plato, Kant defines human nature in terms of reason and the freedom that reason makes possible. Because of this definition of human nature, Kant resisted Aristotle’s prescriptive definition of what it means to be fulfilled and the detailed laws which hinge on that definition. He saw that if human beings are presented with a list of laws, this actually limits the freedom which is a distinctive part of their nature and makes the exercise of reason unnecessary. To be a fulfilled human being is to be a free, rational human being, not to follow lists of laws mindlessly, fit in with convention and take the easiest route through life.
Allowing people their own choices
For Kant the role of the moral philosopher must be to help people to reason out the principles which they should follow and then to choose to follow those principles freely, not to tell people what to do specifically. Think about it – is the better teacher the one who enables students to do things themselves so they are capable when teachers are no longer around, or the one who just gives the students the answers to fill in on the exam papers? Aristotle’s approach to moral philosophy could be seen as almost controlling, undermining the essential roles of reason and freedom and preventing people from finding the fulfilment he wants them to find. For Kant the role of the moral philosopher is difficult, similar to the role of a good teacher or a good parent. It involves helping people only at a distance, allowing them to make their own decisions and accepting the risk that they might make a mistake, even in the knowledge that that mistake might be catastrophic and irreversible.
Think about learning to drive, or teaching somebody to drive. How hard is it to allow an inexperienced teenager to take the wheel for themselves, risking the health and lives of numbers of people in the process? When does the good instructor allow the learner driver to go solo?
a. On the first lesson, to see what happens?
b. After a good grounding in theory and some sessions in a car park?
c. Never – it is safer that way?
Kant's categorical imperative
The moral philosopher can suggest the basic principles which might guide rational, free decisions. For Kant all free, moral decisions should be guided by the categorical imperative, a single simple principle derived from human experience, which, it seems, really does command all free, rational beings. This principle is, however, all too easy to describe in ways that can be misunderstood and misapplied, wilfully or otherwise. In the Groundwork for the Metaphysics of Morals(1785), Kant put forward more than six wordings of the principle, which can be explained in terms of three different ways of describing it. It is important to remember that Kant never intended these wordings to be considered, let alone applied, separately. He believed that they were ways of gesturing towards the same essential law, not a law which he had invented or which could be formulated and applied mindlessly. He believed they together made up a command which is inherent in the nature of human beings but which resists being codified because doing so would remove that which is also inherent in human nature – freedom.
Seeing others as lesser or equal
In other words Kant asks people to consider what would happen if everybody’s actions set a precedent for others to copy. What would happen if some people through their actions use people as a means to an end, effectively assuming that some people are worth less than others, even nothing at all? It is irrational to think that we can allow some people to do things which others are not allowed to do, that doing something will not give others licence to do the same and that equals should be treated as more, or less, important than each other. Reason dictates that humanity must be respected for itself, that selfish urges or emotional preferences must come second to a basic respect for human life. Reason dictates that we must act fairly, consistently, according to principle and not unjustly, instinctively or without sense.
When expressed like this Kant’s moral philosophy ceases to seem so complicated and alien. The American philosopher Allen Wood pointed out that many people's reaction to Kant’s ethics resembles an allergic reaction: they reject Kant really without rational consideration and argument. He goes on to speculate that this might be because most people, particularly in the English-speaking world, first engage with Kant through the Groundwork. The Groundwork is short, but it is not an easy work to begin a study of Kant with. Many short works conceal difficult core theses – think about Animal Farm, which is not a simple introduction to Orwell; Jude the Obscure is shorter than many of Hardy’s great novels but it is certainly not easier, the poems of William Blake, ee cummings and RS Thomas are often short, but their apparent simplicity is misleading.