The idea of law not only supports the whole fabric of his physical philosophy, but moulds his convictions on human life and imparts to his poetry that contemplative elevation by which it is pervaded. It is from this ground that he makes his most powerful assault on the strongholds of superstition. Nature is thus declared to be free from the arbitrary and capricious agency of the gods:-- Libera continuo dominis privata superbis[47]. Man also is under the same law, and is made free by his knowledge and acceptance of this condition. A sense of security is thus gained for human life; a sense of elevation above its weakness and passions, and the courage to bear its inevitable evils[48]. This absolute reliance on law does not act upon his mind with the depressing influence of fatalism. Although the fortunes of life and the phases of individual character are said to be the results of the infinite combinations of blind atoms, yet man is made free by knowledge and the use of his reason. Notwithstanding the original constitution of his nature, arising out of influences over which there is no control, he still has it in his power to live a life worthy of the gods:-- Illud in his rebus videor firmare potesse, Usque adeo naturarum vestigia linqui Parvola, quae nequeat ratio depellere nobis Ut nil inpediat dignam dis degere vitam[49]. From these high places of his philosophy,--'the "templa serena" well-bulwarked by the learning of the wise'[50] he derives not only a sense of certainty in thought and security in life, but also his wide contemplative view, and his profound feeling of the majesty of the universe. The idea of universal law enables him to apprehend in all the processes of Nature a presence which awakens reverence and enforces obedience. This idea imparts unity of tone to the whole poem, informs its language, and seems to mould the very rhythm of its verse. (2) But a closer view brings another aspect of the world into light; viz. the interdependence of all things on one another. There is not only fixed order, but there is also infinite mobility in Nature. The sum of all things remains unchanged, though all individual existences decay and perish. So too the sum of force remains the same[51]. There is no rest anywhere; all things are continually changing and passing into one another; decay and renovation form the very life and being of all things. Nothing is ever lost. 'Nature repairs one thing from another, and allows of no birth except through the death of something else':-- Haud igitur penitus pereunt quaecumque videntur, Quando alid ex alio reficit natura nec ullam Rem gigni patitur nisi morte adiuta aliena[52]?