The principle of individuation and the co-ordinates of conduct.

Theories can be of two kinds, ‘disciplines of thought’ or ‘speculative hypotheses’. ‘principle of individuation’ provides a discipline of thought capable of embracing mathematical equation, dimensions of physics, biological interaction between individual and environment, and psychosomatic problems encountered in medicine and in so-called para-psychology. It indicates not only lines along which divergent schools of psychological thought and inquiry have developed; it gives order and clarity to various interpretations of conduct suggested, and hypotheses put forward for experimental investigation without which collection of data becomes confused and unproductive. It also gives statistical treatment of quantitative studies their appropriate place and function as a means of determining degree to which any qualities assessed are in fact genuine co-ordinates of conduct and dimensions of personality.