Circular Reasoning

In recent times, circular reasoning has become increasingly relevant in various contexts. What is "circular logic" argument? - Philosophy Stack Exchange. Circular reasoning is not a formal logical fallacy but a pragmatic defect in an argument whereby the premises are just as much in need of proof or evidence as the conclusion, and as a consequence the argument fails to persuade. Here is an example of a valid circular reasoning proof using the reiteration (R) inference rule.

Is circular reasoning always a fallacy? It's important to note that, circular reasoning...is a logical fallacy in which the reasoner begins with what they are trying to end with. The components of a circular argument are often logically valid because if the premises are true, the conclusion must be true. logic - Difference between Tautology and Circular Reasoning ....

Similarly, often it is considered that a tautology is the same as a circular reasoning. However, in the Wikipedia entry of Tautology (language), it mentioned that circular reasoning and tautology are differ... Another key aspect involves, circular reasoning would, literally, be "if A and B then A", or, informally, when A is replaced in the premise by some A' transparently equivalent to it. Even then it is not logically wrong, just substantively uninformative, and hence an informal fallacy.

logic - What kind of circularity, if any, is it acceptable for a .... An argument is premise-circular if its conclusion is amongst its premises. A rule-circular argument, by contrast, is an argument of which the conclusion asserts something about an inferential rule that is used in the very same argument.

Building on this, if the Bible contains circular reasoning, does it discredit it?. Circular reasoning doesn't "discredit" any point of view --if anything, it demonstrates internal consistency. However, it also doesn't provide any external support for a point of view. It has no legitimate force against anyone not already convinced of the conclusion. This is a structural issue entirely independent of the question of whether we're considering the Bible or something else.

From another angle, what is the problem with using circular reasoning? What, specifically, is the problem with circular logic/reasoning? I think it's invalid. For some reason, everyone knows that it's wrong to use, but is there anything more to it than that? Is 'cogito ergo sum' false?

The latter made it clear how easily we trip on undefined terms. Descartes's Cartesian Circle makes it clear that he had no issues with the irony of ambiguity and circular reasoning. Similarly, but if we define key terms to establish context, can't we remove Descartes circularity and provide weight to his original claim? That something can be justified through circular reasoning doesn't make it fallacious. What makes it fallacious is if it can only be justified through circular reasoning.