1724– 1804

Maxim: ‘Act only on that maxim whereby thou canst, at the same time, will that it should become a universal law.’

IMMANUEL KANT was a German academic and philosopher who made a major contribution to the Enlightenment period of Western philosophy in eighteenth-century Europe. Born into a strict and pious household, Kant entered his local university at Kӧnigsberg, East Prussia, at the age of sixteen to study philosophy, mathematics and logic. He remained at the university as student, scholar and professor for the rest of his life. Stories abound of the simplicity of Kant’s life, with one apocryphal myth stating that Kant was so meticulous in his daily routine that his neighbours set their clocks according to the time he left the house for his afternoon walk. It is also believed that Kant never travelled any further than ten miles from Kӧnigsberg during his lifetime and spent an entire decade in self-imposed isolation from colleagues and associates in order to devote himself entirely to producing his most famous work, The Critique of Pure Reason (1781).

Kant’s principal project was to attempt to synthesise the differing strands of rationalism and empiricism that had dominated Western thought during the Age of the Enlightenment. Whereas a rational perspective laid claim to the notion that human knowledge is acquired through deductions based on existing ideas, the empiricist perspective promoted the view that reasoning is based on observation alone. Central to Kant’s “critique” is the concept of reason existing a priori or separate to human experience and the processes through which the human mind shapes our understanding of the world. For Kant, the human mind does not constitute an empty vessel that is filled through contact and experience of the world, but rather, the human mind actively acquires knowledge by processing the information it observes. Thus the human mind does not construct the world around us; instead our cognitive faculties reflect how the mind perceives them. In Kant’s words: “We can cognise of things a priori only what we ourselves have put into them.”

By concentrating on the primacy of human autonomy, Kant argued that human understanding is the source of the general laws of nature that structure experiences. Kant expanded this notion to posit that human reason provides the grounding for moral law, which in turn acts as the basis for belief in God, freedom and immortality. Thus scientific knowledge, morality and religion remain consistent with one another due to the pre-eminence of the human autonomy.

In terms of moral law or ethics, Kant suggested the existence of a “categorical imperative” or a supreme moral principle of universality. Moral judgements, for Kant, are determined according to the construction of what he termed “maxims”, or the principles that guide actions. In basic terms, the will to act on a maxim should take into consideration its universal implications.

In Groundwork of the Metaphysics of Morals (1785), Kant uses the example of his borrowing money in a desire to increase his wealth. In the scenario, the moneylender subsequently dies, leaving no record of the transaction. Should Kant then deny borrowing the money? To test his new maxim, Kant asks if it would be permissible as a universal rule for everyone to deny ever borrowing money and concludes that it would not as this would render the practice of lending money entirely obsolete and impossible, regardless of the individual circumstances. Thus Kant’s statement – “Act only on that maxim whereby thou canst, at the same time, will that it should become a universal law” – proposes that in order to act with moral freedom, the maxims or will to act should be tested as universal laws to determine if they are morally permissible.