It is well known that many hysterical subjects exhibit a remarkable development of the subconscious life, amounting, in many cases, to that most interesting phenomenon known as double personality. It has often been argued that the performances of these 'second personalities' are essentially different from the merely automatic movements of ordinary people--so different, in fact, as to compel us to accept the name 'second personality' as a literal expression of the real state of things. Against this view it is urged that we underestimate the automatic powers of the normal subject. We are told that many of the acts which we usually do quite consciously might really be done without consciousness. In support of this assertion such facts are pointed out, as men completely undressing without knowing it, when their attention is distracted by other matters. If this latter explanation is to hold, however, something more than assertion must be forthcoming. The limit of automatism is something that is essentially capable of demonstration by experimental methods, and its investigation forms the subject of this paper. (PsycINFO Database Record (c) 2012 APA, all rights reserved)