During his last fifteen years Pope's original work was done chiefly in two very closely related fields, first in a group of what he called 'Moral' essays, second in the imitation of a few of the Satires and Epistles of Horace, which Pope applied to circumstances of his own time. In the 'Moral' Essays he had intended to deal comprehensively with human nature and institutions, but such a systematic plan was beyond his powers. The longest of the essays which he accomplished, the 'Essay on Man,' aims, like 'Paradise Lost,' to 'vindicate the ways of God to man,' but as regards logic chiefly demonstrates the author's inability to reason. He derived the ideas, in fragmentary fashion, from Bolingbroke, who was an amateur Deist and optimist of the shallow eighteenth century type, and so far was Pope from understanding what he was doing that he was greatly disturbed when it was pointed out to him that the theology of the poem was Deistic rather than Christian [Footnote: The name Deist was applied rather generally in the eighteenth century to all persons who did not belong to some recognized Christian denomination. More strictly, it belongs to those men who attempted rationalistic criticism of the Bible and wished to go back to what they supposed to be a primitive pure religion, anterior to revealed religion and free from the corruptions and formalism of actual Christianity. The Deistic ideas followed those expressed in the seventeenth century by Lord Herbert of Cherbury, brother of George Herbert, who held that the worship due to the Deity consists chiefly in reverence and virtuous conduct, and also that man should repent of sin and forsake it and that reward and punishment, both in this life and hereafter, follow from the goodness and justice of God.] In this poem, as in all Pope's others of this period, the best things are the detached observations. Some of the other poems, especially the autobiographical 'Epistle to Dr. Arbuthnot,' are notable for their masterly and venomous satirical sketches of various contemporary characters. Pope's physical disabilities brought him to premature old age, and he died in 1744. His declining years were saddened by the loss of friends, and he had never married, though his dependent and sensitive nature would have made marriage especially helpful to him. During the greater part of his life, however, he was faithfully watched over by a certain Martha Blount, whose kindness he repaid with only less selfishness than that which 'Stella' endured from Swift. Indeed, Pope's whole attitude toward woman, which appears clearly in his poetry, was largely that of the Restoration. Yet after all that must be said against Pope, it is only fair to conclude, as does his biographer, Sir Leslie Stephen: 'It was a gallant spirit which got so much work out of this crazy carcase, and kept it going, spite of all its feebleness, for fifty-six years.'