As he told his friend Trelawny, he used the word Atheism "to express his abhorrence of superstition; he took it up as a knight took up a gauntlet, in defiance of injustice." But Shelley believed too much to be consistently agnostic.

He believed so firmly and intensely in his own religion--a kind of passionate positivism, a creed which seemed to have no God because it was all God--that he felt convinced he only needed to destroy accepted figments, for the light which blazed around him to break through and flood the world with beauty.

Shelley can only be called an Atheist, in so far as he maintained the inadequacy of hitherto received conceptions of the Deity, and indignantly rejected that Moloch of cruelty who is worshipped in the debased forms of Christianity.

He was an Agnostic only in so far as he proclaimed the impossibility of solving the insoluble, and knowing the unknowable.

His clear and fearless utterances upon these points place him in the rank of intellectual heroes.