In spite of the incompleteness of these considerations, I will venture on a few remarks in conclusion of this discussion. The goal towards which the pleasure-principle impels us—of becoming happy—is not attainable; yet we may not—nay, cannot—give up the effort to come nearer to realization of it by some means or other. Very different paths may be taken towards it: some pursue the positive aspect of the aim, attainment of pleasure; others the negative, avoidance of pain. By none of these ways can we achieve all that we desire. In that modified sense in which we have seen it to be attainable, happiness is a problem of the economics of the libido in each individual. There is no sovereign recipe in this matter which suits all; each one must find out for himself by which particular means he may achieve felicity. All kinds of different factors will operate to influence his choice. It depends on how much real gratification he is likely to obtain in the external world, and how far he will find it necessary to make himself independent of it; finally, too, on the belief he has in himself of his power to alter it in accordance with his wishes. Even at this stage the mental constitution of the individual will play a decisive part, aside from any external considerations. The man who is predominantly erotic will choose emotional relationships with others before all else; the narcissistic type, who is more self-sufficient, will seek his essential satisfactions in the inner workings of his own soul; the man of action will never abandon the external world in which he can essay his power. The interests of narcissistic types will be determined by their particular gifts and the degree of instinctual sublimation of which they are capable. When any choice is pursued to an extreme it penalizes itself, in that it exposes the individual to the dangers accompanying any one exclusive life-interest which may always prove inadequate. Just as a cautious business-man avoids investing all his capital in one concern, so wisdom would probably admonish us also not to anticipate all our happiness from one quarter alone. Success is never certain; it depends on the co-operation of many factors, perhaps on none more than the capacity of the mental constitution to adapt itself to the outer world and then utilize this last for obtaining pleasure. Anyone who is born with a specially unfavourable instinctual constitution, and whose libido-components do not go through the transformation and modification necessary for successful achievement in later life, will find it hard to obtain happiness from his external environment, especially if he is faced with the more difficult tasks. One last possibility of dealing with life remains to such people and it offers them at least substitute-gratifications; it takes the form of the flight into neurotic illness, and they mostly adopt it while they are still young. Those whose efforts to obtain happiness come to