  It is the three remaining modes which are the most interesting. To see how they work, consider the following fact. When the dogmatist produces an argument for a claim, P, either he produces (or gestures at) an argument which goes on forever—an infinite regress—or not. To produce an infinite regress would mean that in offering grounds for his claim P, he gives grounds, Q, and then for that he offers grounds, R, and so on, without ever repeating himself.  If he doesn’t produce an infinite regress, he produces an argument which stops somewhere. In other words, in offering grounds for his claim P, he gives grounds, Q, and then for that he offers grounds, R, etc. and this chain of grounds terminates somewhere. Now there are two possibilities, either this chain terminates in the same claim with which it started (P), or it doesn’t. The first of those two cases is a case of a circular argument—an argument for the conclusion P which eventually appeals to P as its own ground. The second case is a case of an argument which starts from unsupported propositions (first principles, or axioms, perhaps), which function as the ‘anchor’ for the proposition P we are trying to prove.  Thus, there are exactly three possibilities for the form an argument propounded by a dogmatist might take: an infinite regress, a reciprocal or circular argument, or one which terminates in a hypothesis.