And here lies the difficulty. Very much must unquestionably have happened in the course of the world's making for which the Laws of Nature as we find them now acting cannot account, and which, therefore, Science cannot attempt to explain. So we are assured by eminent scientific men,--men, too, who desire nothing more than to find an explanation, but are driven, in search of one, as we have already seen Sir W. Crookes, to plead the limitation of our knowledge, and that there may be capabilities in Nature of which we are ignorant. But it remains always true, that what we do not know is not yet part of Science, and that if our scientific information, so far as it goes, is adverse to the Law of Continuity, it is quite unscientific to bring arguments for the law not from our knowledge, but from our lack of it. Still more unscientific is it to proclaim that Science has pronounced judgment in a sense contrary to that of all the evidence hitherto presented to her. Amongst the men of Science who testify as above, we may begin with Herr Du Bois-Reymond, an avowed Evolutionist and Materialist, whom Professor Haeckel styles, "the all-powerful secretary and dictator of the Berlin Academy of Sciences."[44] He can be suspected of no prejudices which would prevent him from accepting Professor Haeckel's cosmogony, if only he found the evidence satisfactory. Far from this, however, he declares,[45] that the history of the universe confronts us with no less than seven problems, for which Science has no solution to offer, and some of which he holds to be for ever insoluble. These he styles "Enigmas," and they are: (1) The nature of Matter and of Force. (2) The origin of Motion. (3) The origin of Life. (4) The apparently designed order of Nature. (5) The origin of sensation and consciousness. (6) The origin of rational thought and speech. (7) Free-will. The first, second, and fifth of these are in the opinion of Du Bois-Reymond "transcendental," or beyond possibility of solution. The others, in his judgment, have certainly not yet been solved, but _perhaps_ may be solved some day. As to the last, he much doubts whether it should not also be classed as "transcendental." * * * * * It thus appears that in the judgment of a competent witness, and one no-wise biassed by preconception or prejudice, so far from it being true that Professor Haeckel's story of the universe is imperiously imposed on us by the results of Science, not one but several great gulfs in the course of that history must have been bridged over somehow, which Science confesses she cannot bridge, so far as her present knowledge goes, that is to say, so far as she is Science at all. Professor Haeckel, it is true, loudly pronounces Du Bois-Reymond's declaration to be mere "dogmatism"[46] of a "shallow and illogical character," and he undertakes to show that with the help of his own philosophy the enigmas cease to be enigmatical.