Final answer:
The Cartesian circle is a paradox proposed by René Descartes in his Meditations on First Philosophy. It involves circular reasoning in an attempt to prove the reliability of clear and distinct perceptions.
Step-by-step explanation:
The Cartesian circle refers to a paradox proposed by the philosopher René Descartes. In Descartes' Meditations on First Philosophy, he argues that in order to prove the existence of an all-good and non-deceiving God, he needs to establish that clear and distinct perceptions, which form the foundation of his knowledge, are reliable. However, to prove the reliability of clear and distinct perceptions, Descartes relies on the existence of an all-good and non-deceiving God. This circular reasoning is known as the Cartesian circle.