It's quite complicated and sounds circular, but we've worked out a way of calculate a Web site's importance.
— Larry Page

My neighbor has a circular driveway... he can't get out.
Steven Wright circular quote

Clutter is the disease of American writing. We are a society strangling in unnecessary words, circular constructions, pompous frills and meaningless jargon.
— William Zinsser

Who so desireth to know what will be hereafter, let him think of what is past, for the world hath ever been in a circular revolution; whatsoever is now, was heretofore; and things past or present, are no other than such as shall be again: Redit orbis in orbem.
— Sir Walter Raleigh

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.
— circular quotation by Sextus Empiricus