One of the most important thinkers of all time was the German philosopher Immanuel Kant, who lived between 1724 and 1804. attended the University of Königsberg where he studied math and science. Distinguished professor of metaphysics and logic, was also an advocate for the rights of man and representative system of government. He founded his thoughts in a critical philosophy expressed in his three works: Critique of Pure Reason (1781), Critique of Practical Reason (1788) and Critique of Judgement (1790). He claimed that knowledge is the result of reason and the senses and that knowing means finding the objects in the visible world that the reason the law has been structured previously. One of his thesis is the impossibility of making synthetic judgments a priori, as would be the metaphysics.
In his Critique of Practical Reason says that the reason determines all actions pertaining to morality, and that the duty is the same for all men, regardless of any disclosure or religion.
The German idealists of the early nineteenth century, as Schelling, Hegel, Fichte and Schopenhauer, is based on Kantian philosophy.