The measurement of mind appears to constitute a problem generally different from that encountered in the measurement of matter. From the viewpoint of scientific methodology, however, the differences between mental measurement and physical measurement are not as great as they sometimes appear. The major difficulty involves a proper clarification of the mind we measure and, unfortunately, this clarification is a little more difficult than the clarification of the matter we measure. In order to achieve this clarification, it is necessary to reorient some of our habitual ways of thinking by taking several specific steps.