Davidson distinguishes between an operational term and a dynamic term in order to clarify his conception of malingering. Dynamically we must consider malingering as evidence of an emotional disturbance, yet for operational purposes it is necessary to follow the legal definition if the psychiatrist is to be useful in the courts of justice. In the witness box the psychiatrist either accepts the semantic strait jacket imposed by juridical thinking or he is quite literally ruled out of court and his usefulness ceases. Davidson then goes on to describe the differential diagnosis between malingered evidences of psychosis and genuine psychoses. The difficulty in the diagnosis is usually based on the fact that psychiatrists find it distasteful to brand a patient a malingerer. He concludes: 'In our patient-oriented philosophy, sympathy is admittedly a prime requisite. But softness of the heart need not imply softness of the head.'