From this admirable passage till the close of the third book there is an union of philosophy, of majesty, and pathos, which hardly ever has been equalled. The incapacity of the highest power and wisdom, as exhibited in so many instances, to exempt from the common lot of man, the farewell which we must bid to the sweetest domestic enjoyments, and the magnificent _prosopopœia_ of Nature to her children, rebuking their regrets, and the injustice of their complaints, are altogether exceedingly solemn, and affecting, and sublime. The two leading tenets of Epicurus concerning the formation of the world and the mortality of the soul, are established by Lucretius in the first three books. A great proportion of the fourth book may be considered as episodical. Having explained the nature of primordial atoms, and of the soul, which is formed from the finest of them, he announces, that there are certain images (_rerum simulacra_,) or effluvia, which are constantly thrown off from the surface of whatever exists. On this hypothesis he accounts for all our external senses; and he applies it also to the theory of dreams, in which whatever images have amused the senses during day most readily recur. Mankind being prone to love, of all the phantoms which rush on our imagination during night, none return so frequently as the forms of the fair. This leads Lucretius to enlarge on the mischievous effects of illicit love; and nothing can be finer than the various moral considerations which he enforces, to warn us against the snares of guilty passion. It must, however, be confessed, that his description of what he seems to consider as the physical evils and imperfect fruition of sensual love, forms the most glowing picture ever presented of its delights. But he has atoned for his violation of decorum, by a few beautiful lines on connubial happiness at the conclusion of the book: “Nam facit ipsa suis interdum femina factis, Morigerisque modis et mundo corpore culta, Ut facile assuescat secum vir degere vitam. Quod super est, consuetudo concinnat amorem; Nam, leviter quamvis, quod crebro tunditur ictu, Vincitur id longo spatio tamen, atque labascit: Nonne vides, etiam guttas, in saxa cadenteis, Humoris longo in spacio pertundere saxa?”—IV. 1273.