Among leading sociologists Immanuel Kant was a German philosopher who is considered the pivotal figure of modern philosophy. Kant took himself to have effected a Copernican revolution in philosophy. Kant's beliefs continue to influence contemporary philosophy, especially the fields of metaphysics and epistemology. Kant regarded the basic categories of the human mind as the transcendental "condition of possibility" for any experience. Kant was one of the earliest exponents of the idea that perpetual peace could be secured through universal democracy and international cooperation. Kant wanted to put an end to an era of futile and speculative theories of human experience, while resisting the skepticism of thinkers such as David Hume.
Kant believed that the concepts of space and time are integral to all human experience, as are our concepts of cause and effect. Kant aimed to resolve disputes between empirical and rationalist approaches. Kant argued that experience is purely subjective without first being processed by pure reason.