But of course these two "arguments"--that figurative language is necessary to define democracy, and that democracy permits such luxuries as figurative language - are really two faces of a single argument, an argument defining democracy, in part, as that form of government which recognizes the necessity of certain luxuries.
(Source: Bogel, Fredric V. "Understanding Prose." Teaching Prose. Ed. Frederic V. Bogel and Katherine K. Gottschalk. New York: W. W. Norton Company, Inc., 1988. 172. )
Shelley made a number of claims in Necessity , including that one's beliefs are involuntary, and, therefore, that atheists do not choose to be so and should not be persecuted. Towards the end of the pamphlet he writes: "the mind cannot believe in the existence of a God."  Shelley signed the pamphlet, Thro' deficiency of proof, AN ATHEIST,  which gives an idea of the empiricist nature of Shelley's beliefs. According to Berman, Shelley also believed himself to have "refuted all the possible types of arguments for God's existence,"  but Shelley himself encouraged readers to offer proofs if they possess them.
In the course of this enquiry I found that much more had been done than I had been aware of, when I first published the Essay. The poverty and misery arising from a too rapid increase of population had been distinctly seen, and the most violent remedies proposed, so long ago as the times of Plato and Aristotle. And of late years the subject has been treated in such a manner by some of the French Economists; occasionally by Montesquieu, and, among our own writers, by Dr. Franklin, Sir James Stewart, Mr. Arthur Young, and Mr. Townsend, as to create a natural surprise that it had not excited more of the public attention.