How did Kant argue that people should be treated as ends rather than merely as means?

Immanuel Kant argued that people should be treated as ends rather than merely as means through his formulation of the categorical imperative, which states: "So act that you treat humanity in your own person and in the person of everyone else always at the same time as an end and never merely as means."12

This principle is central to Kant’s moral philosophy, which emphasizes that rational beings possess an inherent worth that must be respected. While the connection between this formula and his first formulation—acting only on maxims that can be willed as universal laws—is not entirely explicit, the underlying logic suggests that because individuals choose for themselves, they inherently treat themselves as ends. Therefore, to act in accordance with a universal law that applies to all rational beings, one must extend that same respect to everyone else.12

Treating someone "merely as a means" is exemplified by practices such as slavery, which Kant firmly opposed. Modern Kantians interpret this requirement as a rejection of sacrificing the rights of any individual to benefit others, distinguishing his deontological approach from utilitarianism.12