When the Living Universe builds a house, it builds it out of its own soul substance; while man sleeps and loiters, the Unconscious ceaselessly toils. In the phrase "grows by decays," Emerson embodies, I believe, the law of the conservation of energy. The magazine of divine power is exhaustless; does energy sink out of sight here, it is only to reappear yonder; the tree decays, but out of its fertilizing substance new plants may spring up; the coal under the steam boiler of the locomotive is consumed, but the swart goblin has lost no whit of his might: he just slips darkling up into the steam, makes the driving-rods his swift-shuttling arms, and, grasping with his steel fingers the felloes of the wheel, whirls you half a thousand miles over the green bulge of the earth ere set of sun, The mystic Power grows by decays; and also, by "the famous might that lurks in reaction and recoil," reconciles apparent antinomies and opposites, and is the agent that visits evil upon the head of the evil doer and mercy upon the merciful. If a heavy body be rolled up an inclined plane, it acquires potential and kinetic energy just equal to the force expended in getting it there, and in reaction develops such a famous might that, if massive enough, it will knock you down if you stand in its way. If you lift the big pendulum of the clock in the corner, you also confer latent, or reactionary, energy upon it. Only it is of course hyperbolical for the poet to say that reaction is potent enough to actually freeze flame and make ice boil your kettle. That is only one of Emerson's rhetorical Chinese crackers, his startling thaumaturgic way of illustrating his thesis. The key-thought of the essay 'Spiritual Laws,' to which the occult lines we are considering were prefixed, is, Be noble; for, if you are not, your face and life will, by the law of reaction and return, publish your lapse. Punishment and reward are fruits that ripen unsuspected in the deeds of men. The pertinency and application of many of Emerson's titles are not at once apparent. In 'Merops' the bard affirms that in his high philosophical soarings he cares not whether he can at once ticket his intuitions and perceptions with names or not. Merops was changed into an eagle, says Ovid, and placed among the constellations,--hence, I suppose, is selected by Emerson as a good type of the kind of soaring thinker he is describing. That he also has in mind that Merops was the putative father of Phaethon is shown perhaps by the allusion (in the last stanza) to Phaethon's mishap:-- "Space grants beyond his fated road No inch to the god of day, And copious language still bestowed One word, no more, to say."