Cartesian Circle

The Cartesian circle is a potential mistake in reasoning attributed to René Descartes.

Descartes argues – for example, in the third of his Meditations on First Philosophy – that whatever one clearly and distinctly perceives is true: "I now seem to be able to lay it down as a general rule that whatever I perceive very clearly and distinctly is true." (AT VII 35) He goes on in the same Meditation to argue for the existence of a benevolent God, in order to defeat his skeptical argument in the first Meditation from the possibility that God be a deceiver. He then says that without his knowledge of God's existence, none of his knowledge could be certain. The argument takes this form: 1) Descartes' proof of the reliability of clear and distinct perceptions takes as a premise God's existence as a non-deceiver. 2) Descartes' proofs of God's existence presuppose the reliability of clear and distinct perceptions.

Read more about Cartesian Circle:  Descartes' Contemporaries, Modern Commentators, Sources and References

Famous quotes containing the word circle:

    Everything here below beneath the sun is subject to continual change; and perhaps there is nothing which can be called more inconstant than opinion, which turns round in an everlasting circle like the wheel of fortune. He who reaps praise today is overwhelmed with biting censure tomorrow; today we trample under foot the man who tomorrow will be raised far above us.
    —E.T.A.W. (Ernst Theodor Amadeus Wilhelm)