Martyrs, missionaries, crusaders, nihilists,--enthusiasts of any kind who are swayed by impulses largely below the threshold of ordinary consciousness,--these men bring to bear on human affairs a force more concentrated and at higher tension than deliberate reason can generate. They are virtually carrying out self-suggestions which have acquired the permanence of _idées fixes_. Their fixed ideas, however, are not so isolated, so encysted as those of true hysterics. Although more deeply and immutably rooted than their ideas on other matters, these subliminal convictions are worked in with the products of supraliminal reason, and of course can only thus be made effective over other minds. A deep subliminal horror, generated, say, by the sight of some loathsome cruelty, must not only prompt hallucinations,--as it might do in the hysteric and has often done in the reformer as well,--it must also, if it is to work out its mission of reform, be held clearly before the supraliminal reason, and must learn to express itself in writing or speech adapted to influence ordinary minds. * * * * * We may now pass from the first to the second of the categories of disintegration of personality suggested at the beginning of this chapter. The cases which I have thus far discussed have been mainly cases of _isolation_ of elements of personality. We have not dealt as yet with _secondary personalities_ as such. There is, however, a close connection between these two classes. There are cases, for example, where a kind of secondary state at times intervenes--a sort of bewilderment arising from confluent _idées fixes_ and overrunning the whole personality. This new state is often preceded or accompanied by something of somnambulic change. It is this new feature of which we have here a first hint which seems to me of sufficient importance for the diagnosis of my second class of psychical disintegrations. This second class starts from sleep-wakings of all kinds, and includes all stages of alternation of personality, from brief somnambulisms up to those permanent and thorough changes which deserve the name of dimorphisms. We are making here a transition somewhat resembling the transition from isolated bodily injuries to those subtler changes of diathesis which change of climate or of nutrition may induce. Something has happened which makes the organism react to all stimuli in a new way. Our best starting-point for the study of these secondary states lies among the phenomena of _dream_. We shall in a later chapter discuss certain rare characteristics of dreams; occasional manifestations in sleep of waking faculty heightened, or of faculty altogether new. We have now to consider ordinary dreams in their aspect as indications of the structure of our personality, and as agencies which tend to its modification.