Kant was an original thinker not only in the field of ethics but in virtually every area of philosophy. His reputation skyrocketed during the last two decades of his life, and during the nineteenth century his writings were the most influential philosophical writings in Europe. Many philosophers agreed with his theories and adopted his specialized Kantian vocabulary. Others, however, were less happy with Kant’s elaborate philosophical system and picked away at parts of it, including the categorical imperative.
Kant’s philosophy served as a source of inspiration for the German philosopher, Arthur Schopenhauer. Despite the fact that he adopted many of Kant’s ideas, he also criticised some aspects of his philosophy, especially the Categorical Imperative. For Schopenhauer, the CI simply reduces to the egoistic principle: “I shouldn’t do to others what I don’t want done to myself.” Schopenhauer believed that the human behaviour is guided sometimes by sympathy for others and other times by egoistic concerns for oneself. He argued that truly moral conduct must be sympathetic, an idea contradicted by Kant’s CI.
Another early criticism of the Categorical Imperative is that by the German philosopher Georg Wilhelm Friedrich Hegel. Hegel analysed Kant’s first formulation of the CI: “Act as if the maxim of your action were to become through your will a universal law of nature.” According to Hegel, this formula “is reduced to empty formalism, and moral science is converted into mere rhetoric about duty for duty’s sake.” That is, it does not offer a clear guideline for assessing moral conduct, and it does not provide any specific moral duties that can be followed. While the CI may sound good in theory, it is difficult to apply in real life because it does not acknowledge contradictory actions.
Similarly, Jean Paul Sartre criticises Kant’s philosophy. He argued the fact that Kant’s CI does not provide guidance when facing dilemmas. He supported his idea by using an example from his own experience, during the Nazi occupation of France. Here, a young man is torn between his duty to his country, which impelled him to join the resistance and which would possibly lead to his dead and his duty to his mother who had already lost her other sons to the war. Kant’s ethical theory states that both imperatives are categorical, therefore pulling the young man is two different ways. This proves that the CI is not