Of Shelley's letters, again, we may say that they are unconsciously autobiographical; they are confessions of character, spontaneous, unguarded, abounding with brilliancies and extravagances. They betray his shortcomings, but they attest his generosity and courage; they are the outpourings of a new spirit, who detests what would now be called Philistinism in literature and society; who does not stop to pick his words, or to mix water with the red wine of his enthusiasm. He abandons himself in his letters to the feelings of the moment; he ardently pursues his immediate object by sophistical arguments which convict himself but could never convince a correspondent, and which astonish and amuse the calm reader of after days. 'A kind of ineffable, sickening disgust seizes my mind when I think of this most despotic, most unrequired fetter which prejudice has forged to confine its energies.... Anti-matrimonialism is as necessarily connected with scepticism as if religion and marriage began their course together,' for both are the fruit of odious superstition. He was endeavouring to persuade Harriet Westbrook to join him in testifying by example against the obsolete and ignoble ceremony of the marriage service, which he held to be a degradation that no one could ask 'an amiable and beloved female' to undergo. In Shelley's case, as in Byron's, the letters are of inestimable biographical value as witnesses to character, as reflecting the vicissitudes of a life which was to the writer more like the 'fierce vexation of a dream' than a well-spent leisurely existence, and as the sincere unstudied expression of his emotions. For all these reasons they are essential to a right appreciation of his magnificent poetry.