Judging by current literature, 2 theoretical psychology in America has become pretty thoroughly convinced of the value of symbolic logic. As a philosopher I cannot conceal my pleasure over this recognition of the importance to psychology of one of the disciplines which by tradition is included in philosophy. My own conviction is that we are suffering today from too great a separation of the specialized research of the sciences and the more general, synthetic inquiry of philosophy, and that any sincere attempt to bring understanding and cooperation between these two interests is to be wholeheartedly encouraged. So if I point out what seem to me to be certain dangers in the current trend in psychology, it is not because I wish to disparage it, but rather because I fear that, if it grows too rapidly, its roots will be too shallow, and it will die almost as quickly as it has grown, to be replaced, perhaps, by an even greater suspicion of everything philosophical than that which it had to overcome. The dangers I shall indicate may be said to be all 'psychological,' but surely no psychologist would add 'merely' to this characterization (though I fear some logical positivists might). For, they are real dangers for which psychology, as a human enterprise, must be on the alert. They are, however, dangers, not insuperable obstacles.The recognition and appraisal of these dangers in the use of symbolic logic in current psychology (or, as I shall call it, the 'logicizing of psychology') may perhaps be best introduced by 1 Developed from a talk given to the Psychology Seminar at Stanford University on May 26, 1941, and read before the Philosophical Club of Stanford University on August 2, 1941. 1 See, e.g., bibliographies in (44, 26).