"Kritik der reinen Vernunft" by Immanuel Kant is a philosophical work published in 1781. Kant seeks to determine the limits and scope of metaphysics by examining reason itself. He challenges both empiricist and rationalist traditions, introducing revolutionary ideas about space, time, and knowledge. The central question: How can we possess knowledge that is both independent of experience and adds something new to our understanding? This groundbreaking work sparked controversy and fundamentally shaped Western philosophy.