A similar defect in the treatment of this question by evolutionists we find in the works of Oscar Schmidt, Gustav Jaeger, and others. Even Emil DuBois-Reymond, who, in his celebrated and eloquent lecture on "The Limits of the Knowledge of Nature," given before the assembly of scientists at Leipzig, 1872, asserts so energetically that the origin of sensation and consciousness is inexplicable (see next section), seems to {125} take the origin of self-consciousness for granted, and as needing no further explanation, if only consciousness is once present. Since, then, the scientists leave us without a sufficient answer to the question respecting the origin of self-consciousness and of moral self-determination, we shall have to turn to the philosophers. Here, indeed, we find rich definitions and genetic analyses, but none that lead us any farther than to the information that consciousness is the necessary condition of self-consciousness; that animal instinct is the necessary antecedent condition of moral self-determination. Yet in the works of these very philosophers who are inclined to a mechanical and "monistic" view of the world, we find that they directly avoid the question as to the origin of self-consciousness and of moral self-determination. As soon as they are led near it, in the course of reasoning in their works, they suddenly turn aside again to the quite different questions of the connection between brain and soul, between physical and psychical, external and internal processes, etc. Evidently they feel that with this question they have arrived at the weak point of their system. That here is a weak point, we clearly see in the case of D. F. Strauss, a leading advocate of modern naturalism, and the greatest philosophic scholar of that school. It is true, in his "Postscript as Preface," as we saw before, he mentions the origin of self-consciousness as one of the points which need special explanation; but he seems to have made this acknowledgment more with the purpose of showing that DuBois-Reymond, in admitting the origin of self-consciousness to be explainable, has no longer any reason to contest the explicability of the {126} origin of sensation and consciousness; for in his work on "The Old Faith and the New," he did not enter into that question at all. On the other hand, he makes in his last-mentioned work a remarkable confession. In answering the question--how do we determine our rule of life?--he comes to speak of the position of man in nature, traces a law of progress in nature, and says: "In this cumulative progression of life, man is also comprised, and, moreover, in such wise that the organic plasticity of our planet (provisionally, say some naturalists, but that we may fairly leave an open question) culminates in him. _As nature can not go higher, she would go inwards._ 'To be reflected within itself,' was a very good expression of Hegel's. Nature felt herself already in the animal, but