If then the matter of this present visible universe be not capable of itself, that is to say, in virtue of the forces and qualities with which it has been endowed, of generating life; but if we must look to the unseen universe for the origin of life, this would appear to show that the peculiar collocation of matter which accompanies the operations of life is not a mere grouping of particles of the visible universe, but implies likewise some peculiarity in the connection of these with the unseen universe. May it not denote in fact some peculiarity of structure extending to the unseen? In fine, to go a step further, may not life denote a peculiarity of structure which is handed over not merely from one stage to another—from the invisible to the visible—but which rises upwards from the very lowest structural depths of the material of the universe, this material being regarded as possessed of an infinitely complex structure such as we have pictured to our readers in a previous part of this chapter (Art. 220). If we suppose any such peculiarity to accompany life we cannot fail at once to see the impossibility of its originating in the visible universe alone. 233. Again, it is well known to many of our readers that discussions have frequently arisen regarding the peculiar place and function of life in the universe. What is its relation to energy? it certainly does not create energy—what then does it do? One way of replying to this question is indicated in the following passage, which we quote at length from an article on ‘The Atomic Theory of Lucretius,’ in the _North British Review_ for March 1868:— ‘It is a principle of mechanics that a force acting at right angles to the direction in which a body is moving does no work, although it may continually and continuously alter the direction in which the body moves. No power, no energy, is required to deflect a bullet from its path, provided the deflecting force acts always at right angles to that path....