A subconscious personality is a condition where complexes of subconscious processes have been constellated into a personal system, manifesting a secondary system of self-consciousness endowed with volition, intelligence, etc. Such a subconscious personality is capable of communicating with the experimenter and describing its own mental processes. It can, after repression of the primary personality, become the sole personality for the time being, and then remember its previous subconscious life, as we all remember our past conscious life, and can give full and explicit information regarding the nature of the subconscious process. By making use of the testimony of a subconscious personality and its various manifestations, we can not only establish the actuality of subconscious processes and their intrinsic nature in these conditions, but by prearrangement with this personality predetermine any particular process we desire and study the modes in which it influences conscious thought and conduct. For instance, we can prescribe a conflict between the subconsciousness and the personal consciousness, between a subconscious wish and a conscious wish, or volition, and observe the resultant mental and physical behavior, which may be inhibition of thought, hallucinations, amnesia, motor phenomena, etc. The possibilities and limitations of subconscious influences can in this way be experimentally studied. Subconscious personalities, therefore, afford a valuable means for studying the mechanism of the mind.[78] The conclusion, then, seems compulsory that the subconscious processes in many conditions, particularly those that are artificially induced and those that are pathological, are _coconscious_ processes. There are other phenomena, however, which require the postulation of a subconscious process, yet which, when the subconscious is searched by the same methods made use of in hysterical phenomena, do not reveal explicit evidence of coconsciousness. An analysis of the subconscious revelations as well as the phenomena themselves seems to favor the interpretation that in some cases the underlying process is in part and in others wholly _unconscious_. The only ground for the interpretation that all subconscious processes are wholly conscious is the assumption that, as some are conscious, all must be. This is as unsound as the assumption that, because at the other end of the scale some complex actions (e. g., those performed by decerebrated animals) are intelligent and yet performed by processes necessarily unconscious, therefore all actions not under the guidance of the personal consciousness are performed by unconscious processes. If some subconscious processes are unconscious they are equivalent to physiological processes such as, _ex hypothesi_, are correlated with all conscious processes and perhaps may be identified with them. In truth, they mean nothing more nor less than “unconscious cerebration.”