To this theory and its general acceptance we owe chiefly the very wide scope and the philosophical profundity of most modern critical writing of the higher kind. Critics are not content nowadays with taking up a poem, novel, essay, or history, and looking at it by itself as an individual and isolated work of art. They must look into the personal life of the writer; they must discover and estimate all the influences by which he was surrounded; and among these they give a very important place to the condition of the society in which he lived, the political and religious forces which were at work while he was studying, thinking, writing. Briefly, they regard him not as an isolated individual force, but as a manifestation, a result of many forces, as doing his work less by personal volition than as the unconscious agent or representative of the times in which he lived. Consequently a critical edition or appreciation of a great writer has come to be not a purely literary task, but an attempt to unfold the mental and moral condition of a people and a period. Compare, for example, Addison's criticism of the "Paradise Lost," to which in a great measure the general appreciation of that poem is due, with David Masson's "Life of Milton." The former can all be included in a thin duodecimo volume, and has been so printed; the latter, still unfinished, fills several ponderous octavo volumes. Addison concerns himself with the poem itself; Masson writes an elaborate history of Puritanism and of the English people during the development and completion of that religious, social, and political revolution which produced the Commonwealth in Old England and the Puritan emigration to America, with the formation of the religious commonwealths of New England. True, Addison did not undertake to do what Masson undertook, and allowance must be made for the avowed difference between the methods of the two writers. But still that very difference is the significant exponent of the critical spirit of the times in which they lived. The very fact that the Victorian critic has undertaken his tremendous task, which Addison or any man of his time would not have thought of, is significant of the change in critical manner to which we have referred.