Valid and invalid circular logic

[CK the Fat]

Right, we all know what circular reasoning is by now.

A = B and B = C means that A = C, undisputedly. (This is transitive property, as applied to mathematics.

Let's look at some scenarios regarding circular reasoning.

Bob = human. Human = alive. So Bob = alive. This works, because Bob is indeed alive.

Here's another case: Sally = alive. Alive = monkey. But Sally =/= monkey, so this does not work.

Now, these can be argued by saying that Bob nor Sally have to be alive, nor the monkey and in a myriad of ways.

So when exactly is circular logic valid and when is it invalid?

 

[Phoenix]

Circular logic is substantiating a statement which another statement which is in turn substantiated by the first statement.

Your examples aren't circular. Me = God, God = Me is.

 

[Aucune Raison]

Phoenix is right. You're using a flowchart sort of reasoning, which can also be false.

 

[KrytenKoro]

Circular logic is valid if it's right.

Which is the crutch - it's impossible to prove anything with circular logic. So it's useless.

You can start off with assumptions and show what they would lead to - the assumptions can still be wrong, but they at least have a semi-useful system. So it's useful as long as you realize and accept that you are starting off with certain assumptions or givens.

To be completely honest, no logic is ever completely valid, as they all have to start at some arbitrary spot.