Some famous modern philosophers are Immanuel Kant, Friedrich Nietzsche and Rene Descartes, as of 2015. Modern philosophy began in Western Europe during the 17th century. Common around the world, it is not specific to any doctrine or school of thought.
Considered the central figure of modern philosophy, German philosopher Immanuel Kant believed that knowledge is what comes through our senses filtered by the rational mind. Because there is a difference between reality and perception, the world is in itself unknowable. Kant bridged rationalism and empiricism.
German philosopher Friedrich Nietzsche famously declared that God is dead, and questioned existing paradigms of truth at the time, such as Europe's belief that the Christian God is the root of morality and the purpose to life. His questioning of man's trust in reason and his belief of an unconscious motive in its exercise greatly influenced existentialism, nihilism and postmodernism.
French mathematician Rene Descartes is often considered the father of modern philosophy. He posed the modern version of the mind–body problem, contemplating if there is anything man could really know for sure, even his own existence. He concluded that he knows he exists by the very virtue that he can ask whether he exists.