structure for 'Reason'    |     alphabetical list of themes    |     unexpand these ideas

2. Reason / F. Fallacies / 4. Circularity

[line of reasoning which just leads back to its start]

8 ideas
Clear and distinct conceptions are true because a perfect God exists [Descartes]
     Full Idea: That the things we grasp very clearly and very distinctly are all true, is assured only because God is or exists, and because he is a perfect Being.
     From: René Descartes (A Discourse on Method [1637], §4.38)
Once it is clear that there is a God who is no deceiver, I conclude that clear and distinct perceptions must be true [Descartes]
     Full Idea: Once I perceived that there is a God,…and that he is no deceiver, I then concluded that everything that I clearly and distinctly perceived is necessarily true.
     From: René Descartes (Meditations [1641], §5.70)
     A reaction: spotted by Arnauld
It is circular to make truth depend on believing God's existence is true [Arnauld on Descartes]
     Full Idea: How does the author avoid reasoning in a circle when he says that we are sure that what we clearly and distinctly perceive is true only because God exists? But we can be sure that God exists only because we clearly and distinctly perceive this.
     From: comment on René Descartes (Meditations [1641], §5.71) by Antoine Arnauld - Objections to 'Meditations' (Fourth) 214
Descartes is right that in the Christian view only God can guarantee the reliability of senses [Nietzsche on Descartes]
     Full Idea: Even Descartes had a notion that in a Christian mode of thought (where God is a good creator), only God's veracity guarantees to us the judgements of our senses.
     From: comment on René Descartes (Meditations [1641], §5.71) by Friedrich Nietzsche - The Will to Power (notebooks) §436
     A reaction: An unusual defence of the notorious Cartesian Circle. Of course, Descartes claims that God guarantees reason (as 'clear and distinct conception'), not senses, and only reason led Descartes to God.
I know the truth that God exists and is the author of truth [Descartes]
     Full Idea: I have very clearly deduced the following truths, that there is a God who is the author of all that is in the world, and who is the source of all truth.
     From: René Descartes (Preface to 'Principles of Philosophy' [1647], p.180)
One sort of circularity presupposes a premise, the other presupposes a rule being used [Braithwaite, by Devitt]
     Full Idea: An argument is 'premise-circular' if it aims to establish a conclusion that is assumed as a premise of that very argument. An argument is 'rule-circular' if it aims to establish a conclusion that asserts the goodness of the rule used in that argument.
     From: report of R.B. Braithwaite (Scientific Explanation [1953], p.274-8) by Michael Devitt - There is no a Priori §2
     A reaction: Rule circularity is the sort of thing Quine is always objecting to, but such circularities may be unavoidable, and even totally benign. All the good things in life form a mutually supporting team.
Maybe reasonableness requires circular justifications - that is one coherentist view [Field,H]
     Full Idea: It is not out of the question to hold that without circular justifications there is no reasonableness at all. That is the view of a certain kind of coherence theorist.
     From: Hartry Field (Apriority as an Evaluative Notion [2000], 2)
     A reaction: This nicely captures a gut feeling I have had for a long time. Being now thoroughly converted to coherentism, I am drawn to the idea - like a moth to a flame. But how do we distinguish cuddly circularity from its cruel and vicious cousin?
Circular arguments are formally valid, though informally inadmissible [Hanna]
     Full Idea: A circular argument - one whose conclusion is to be found among its premises - is inadmissible in most informal contexts, even though it is formally valid.
     From: Robert Hanna (Rationality and Logic [2006], 2.1)
     A reaction: Presumably this is a matter of conversational implicature - that you are under a conventional obligation to say things which go somewhere, rather than circling around their starting place.