In previous papers we discussed two aspects of state of mind: (I) where it was used to prove an act in issue; I and (2) where it was itself in issue.2 In order to discuss it scientifically it was first necessary to dispose of linguistic differences between modern psychology and the law, because of the attitude of the former toward introspective studies of non-verifiable behavior. After discovering what behavior was referred to by the legal concept, that behavior was discussed in the light of recent psychological study.3 It then appeared that state of mind to prove an act and state of mind in issue were two different phenomena which easily became confused because of the tendency to use a single phrase to cover them both. Further analysis rev...