When there exists harmony one impression leads to, enhances another; we, on the other hand, unconsciously recognise at once what is doing to us, what we in return must do; the mood is indicated, fulfilled, consummated; in plenitude we feel, we are; and in plenitude of feeling and being, we, in our turn, _do_. Neither is such habit of harmony, of scheme, of congruity, a mere device for sucking the full sweetness out of life, although, heaven knows, that were important enough. As much as such a habit husbands, and in a way multiplies, life's sweetness; so likewise does it husband and multiply man's power. For there is no quicker and more thorough mode of selecting among our feelings and thoughts than submitting them to a standard of congruity; nothing more efficacious than the question: "Is such or such a notion or proceeding harmonious with what we have made the rest of our life, with what we wish our life to be?" This is, in other words, the power of the _ideal_, the force of _ideas_, of thought-out, recognised habits, as distinguished from blind helter-skelter impulse. This is what welds life into one, making its forces work not in opposition but in concordance; this is what makes life consecutive, using the earlier act to produce the later, tying together existence in an organic fatality of _must be_: the fatality not of the outside and the unconscious, but of the conscious, inner, upper man. Nay, it is what makes up the _Ego_. For the _ego_, as we are beginning to understand, is no mysterious separate entity, still less a succession of disconnected, conflicting, blind impulses; the _ego_ is the congruous, perceived, nay, thought-out system of habits, which feels all incongruity towards itself as accidental and external. Hence, when we ask which are the statements we believe in, we answer instinctively (logic being but a form of congruity) those statements which accord with themselves and with other statements; when we ask, which are the persons we trust? we answer, those persons whose feelings and actions are congruous with themselves and with the feelings and actions of others. And, on the contrary, it is in the worthless, in the degenerate creature, that we note moods which are destructive to one another's object, ideas which are in flagrant contradiction; and it is in the idiot, the maniac, the criminal, that we see thoughts disconnected among themselves, perceptions disconnected with surrounding objects, and instincts and habits incompatible with those of other human beings. Nay, if we look closely, we shall recognise, moreover, that those emotions of pleasure are the healthy, the safe ones, which are harmonious not merely in themselves (as a musical note is composed of even vibrations), but harmonious with all preceding and succeeding pleasures in ourselves, and harmonious, congruous, with the present and future pleasures in others. V.