 A seventh meaning of rationality resembles the notion of coherence by defining rationality as the absence of a defect. For Bayesians, sure-loss is the epitome of irrationality and coherence is simply its absence. Sorensen has suggested a generalization of this strategy, one where rationality is conceived as the absence of irrationality tout court, just as cleanliness is the absence of dirt. Yet, owing to the long and varied ways that irrationality can arise, a consequence of this view is that there then would be no unified notion of rationality to capture the idea of thinking as one ought to think (Sorensen 1991).