From Chapter 5 ("Washington Intelligence") of Roberta Wohlstetter's Pearl Harbor:

... A willingness to play with material from different angles and in the context of unpopular as well as popular hypotheses is an essential ingredient of a good detective, whether the end is the solution of a crime or an intelligence estimate. This sort of flexibility is probably not good for one's reputation as a sound estimator, since one index to sound judgment is agreement with the hypotheses on which current department policy is based. But intelligence will always be confronted with this choice: whether to be popular or alert.

^z - 2017-11-20