[Footnote 16: _Consciousness_. The antiquated view of Du Bois-Reymond (1872)--that human consciousness is an unsoluble "world-riddle," a transcendent phenomenon in essential antithesis to all other natural phenomena--continues to be upheld in numerous writings. It is chiefly on this that the dualistic view of the world founds its assertion, that man is an altogether peculiar being, and that his personal soul is immortal; and this is the reason why the "Leipsic ignorabimus-speech" of Du Bois-Reymond has for twenty years been prized as a defence by all representatives of the mythological view of the world, and extolled as a refutation of "monistic dogma." The closing word of the discourse, "ignorabimus," was translated as a present, and this "ignoramus" taken to mean that "we know nothing at all"; or, even worse, that "we can never come to clearness about anything, and any further talk about the matter is idle." The famous "ignorabimus" address remains certainly an important rhetorical work of art; it is a "beautiful sermon," characterised by its highly-finished form and its surprising variety of philosophico-scientific pictures. It is well known, however, that the majority (and especially women) judge a "beautiful sermon" not according to the value of the thoughts embodied in it, but according to its excellence as an aesthetical entertainment. While Du Bois treats his audience at great length to disquisitions on the wondrous performances of the genius of Laplace, he afterwards glides over, the most important part of his subject in eleven short lines, and makes not the slightest further attempt to solve the main question he has to deal with--as to whether the world is really "doubly incomprehensible." For my own part, on the contrary, I have already repeatedly sought to show that the two limits to our knowledge of nature are one and the same; the fact of consciousness and the relation of consciousness to the brain are to us not less, but neither are they more, puzzling, than the fact of seeing and hearing, than the fact of gravitation, than the connection between matter and energy. Compare my discourse on _Freedom in Science and Teaching_ (1878), pp. 78, 82, etc.]