The Mode of circular reasoning is the form used when the proof itself which ought to establish the matter of inquiry requires confirmation derived from the matter in this case, being unable to assume either in order to establish the other, we suspend judgement about both.

Scepticism is an ability, or mental attitude, which opposes appearances to judgments in any way whatsoever, with the result that,owing to the equipollence of the objects and reasons thus opposed we are brought firstly to a state of mental suspense and next to a state of unperturbedness or quietude.

To every argument an equal argument is opposed.

By skepticism . . . we arrive first at suspension of judgment, and second at freedom from disturbance.

Skepticism relieved two terrible diseases that afflicted mankind: anxiety and dogmatism.