So matter itself is force and nothing else--or rather it is two forces, electrons (negative electricity) and protons (positive electricity) locked together in a strange conflict whose resistance to interference gives tangibility and “hardness” to the things of the world--all of which sounds rather as if it had been translated from the Rig-Veda. Gone by the board is the idea that matter is the fundamental reality, that nothing can happen in the mind but what has first happened in the brain. But has mind itself to obey the old law? Is it but a more subtile manifestation of the preponderance of exterior forces? We shall have to penetrate yet farther into these fairy halls of science before finding an answer to that question. 2. SOME NEBULOUS MATTERS Of all the facts of the old science, none was more firmly established than what was known as the “Nebular Hypothesis.” The name “hypothesis” clung to it always, because “nebular hypothesis” makes an imposing mouthful of syllables. Yet it was everywhere treated as a fact. Indeed, after the “fact” of the conservation of energy, it was just about the fact of facts. What has become of it now? A. Vibert Douglas, M.B.E., M.Sc., writing in _Discovery_ for August, 1925, says, “The nebular hypothesis of Laplace and the planetesimal hypothesis of Chamberlain have gone into the history of science as great and lasting _monuments_ to their originators.” Monuments! Memorials marking the last resting place of things now dead. How carefully Herbert Spencer used to explain the manner in which a lot of star-dust, scattered somehow through the space marked roughly by the orbit of the planet Neptune, started to contract, revolve, grow warm, and to throw off rings (since known as Jupiter, Saturn, Venus, Earth, Mars, _et cetera_) and ended by central concentration in our glowing sun. There was nothing difficult to understand about the theory except the language in which Spencer couched it--that is, unless one tried to look beyond and into some of the things which it took for granted. In that case certain questions arose. What scattered the dust in the first place? Would it scatter it again, again, and yet again, thus creating the universe of recurrent phenomena imagined by the horror-loving Nietzsche? What force separated the rings from the mass and rolled them neatly up into planets? Why haven’t Saturn’s rings rolled up? Will they, in time? What is keeping them back? These matters, and various details which had been observed but by few, troubled the mathematicians.