But,--apart from this,--What is known concerning this same "Matter"? Has Science so thoroughly fathomed its constitution as to be able to declare that it possesses all the properties we have heard assigned to it,--Sensation and Will, even of the unconscious kind, whatever that may be,--locomotive power,--eternity,--and, in its collective capacity, immensity? So far from this being the case, scientific men who were most willing, and even anxious, to assign to Matter a foremost, if not _the_ foremost, place in Nature, have done so precisely upon the ground, not of our knowledge, but of our ignorance. No better examples need be sought than Professor Huxley, and Professor Tyndall, who alike agreed, in the words of the latter,[54] "to discern in Matter the promise and potency of every form and quality of life." But Huxley took his stand on the declaration, that we know so little about Matter as to make it impossible to say of what it may not be capable, for we cannot so much as be certain of its existence, and use the term only "for the unknown and hypothetical causes of our own states of consciousness,"[55] while Tyndall described the process, whereby the promise and potency are realized, as "the manifestation of a Power absolutely inscrutable to the intellect of man." Speculations thus founded upon the absence of evidence, whatever else they may be, are certainly no part of Science; and when we turn to what, being established by scientific methods, is a possible basis of scientific argument, we find that in every instance it contradicts instead of supporting the assertions we have heard. To begin with the question of Motion, as being both of supreme importance, and one more open than some others to observation and experiment. According to Professor Haeckel's teaching, "movement is an innate and original property of substance," that is to say of Matter, and in consequence, "Substance is everywhere and always in uninterrupted movement and transformation." It is by thus attributing to matter an inherent determination to move that he meets Du Bois-Reymond's difficulty as to the origin of motion.