Let us first go to Shelley's prose, not because it is his "best" work (though some parts of it are exquisitely beautiful, often very powerful, and always chaste), but because prose is less open than verse to false conception and interpretation. In the fine fragment "On Life" he acutely observes that "Mind, as far as we have any experience of its properties, and beyond that experience how vain is argument! cannot create, it can only perceive." And he concludes "It is infinitely improbable that the cause of mind, that is, of existence, is similar to mind." Be it observed, however, that Shelley does not dogmatise. He simply cannot conceive that mind is the _basis_ of all things. The cause of life is still obscure. "All recorded generations of mankind," Shelley says, "have wearily-busied themselves in inventing answers to this question; and the result has been--Religion." Shelley's essay "On a Future State" follows the same line of reasoning as his essay "On Life." He considers it highly probable that _thought_ is "no more than the relation between certain parts of that infinitely varied mass, of which the rest of the universe is composed, and which ceases to exist as soon as those parts change their positions with regard to each other." His conclusion is that "the desire to be for ever as we are, the reluctance to a violent and unexperienced change," which is common to man and other living beings, is the "secret persuasion which has given birth to the opinions of a future state." If we turn to Shelley's published letters we shall find abundant expressions of hostility to and contempt for religion. Those letters may deserve the praise of Matthew Arnold or the censure of Mr. Swinburne; but, in either case, they may be taken as honest documents, written to all sorts of private friends, and never intended for publication. Byron's letters were passed about freely, and largely written for effect; Shelley's were written under ordinary conditions, and he unbosomed himself with freedom and sincerity.