Again, what cannot be is not, and what is can be regarded as an instance of what can be. Individuals who make pseudodiagnoses on the basis of “typica… - Robyn Dawes

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Again, what cannot be is not, and what is can be regarded as an instance of what can be. Individuals who make pseudodiagnoses on the basis of “typical” characteristics—by attending only to the numerator of the likelihood ratio rather than to both numerator and denominator—will similarly be doomed to failure by making diagnoses that are not empirically supported. Because such a diagnostic procedure is based on irrationality, it cannot in general succeed. And similarly, people who argue that both the evidence and its negation support the same conclusion are arguing irrationally, and hence the conclusions will be empirically flawed. The principle is the same.