Cartesian Circle

The Cartesian Circle is a philosophical problem raised by Immanuel Kant concerning Descartes' argument for God's existence and the certainty of clear and distinct perceptions. Descartes claims that we can be sure of our clear and distinct ideas because a perfect God guarantees their clarity, and we can be certain of God's existence because we perceive the truthfulness of these ideas. The issue is that this reasoning appears to rely on the very certainty it seeks to establish, creating a circular reasoning. Essentially, it's like using a standard to verify itself, raising questions about the foundation of knowledge.