In the concluding paragraph of “Two principles”, Freud (2011b) states

The deficiencies of this short paper, which is preparatory rather than expository, will perhaps be excused only in small part if I plead that they are unavoidable. (p. 226)

His humility seems unwarranted when we considered the richness of psychoanalytic ideas that owe their lineage, in part, to this brief “preparatory” paper. David Bell (Chapter Two, this volume) commented that the ideas developed in “Two principles” are present in most of Freud’s other writings and we have seen the immense heuristic value of these concepts in the rich assortment of papers gathered together in this volume. The richness of the contributions in this volume is a testimony to the paramount importance of Freud’s paper in the development of psychoanalytic theory and practice. Indeed, Civitarese maintains that Freud understood the importance of this brief article when he stated:

But I hope it will not escape the notice of the benevolent reader how in these pages too the dominance of the reality principle is beginning. (p. 226)