From time to time Emerson collected and published his lectures under various titles. A first series of _Essays_ came out in 1841, and a second in 1844; the _Conduct of Life_ in 1860, _Society and Solitude_ in 1870, _Letters and Social Aims_ in 1876, and the _Fortune of the Republic_ in 1878. In 1847 he issued a volume of _Poems_, and 1865 _Mayday and Other Poems_. These writings, as a whole, were variations on a single theme, expansions and illustrations of the philosophy set forth in _Nature_, and his early addresses. They were strikingly original, rich in thought, filled with wisdom, with lofty morality and spiritual religion. Emerson, said Lowell, first "cut the cable that bound us to English thought and gave us a chance at the dangers and glories of blue water." Nevertheless, as it used to be the fashion to find an English analogue for every American writer, so that Cooper was called the American Scott, and Mrs. Sigourney was described as the Hemans of America, a well-worn critical tradition has coupled Emerson with Carlyle. That his mind received a nudge from Carlyle's early essays and from _Sartor Resartus_ is beyond a doubt. They were life-long friends and correspondents, and Emerson's _Representative Men_ is, in some sort, a counterpart of Carlyle's _Hero Worship_. But in temper and style the two writers were widely different. Carlyle's pessimism and dissatisfaction with the general drift of things gained upon him more and more, while Emerson was a consistent optimist to the end. The last of his writings published during his life-time, the _Fortune of the Republic_, contrasts strangely in its hopefulness with the desperation of Carlyle's later utterances. Even in presence of the doubt as to man's personal immortality he takes refuge in a high and stoical faith. "I think all sound minds rest on a certain preliminary conviction, namely, that if it be best that conscious personal life shall continue it will continue, and if not best, then it will not; and we, if we saw the whole, should of course see that it was better so." It is this conviction that gives to Emerson's writings their serenity and their tonic quality at the same time that it narrows the range of his dealings with life. As the idealist declines to cross-examine those facts which he regards as merely phenomenal, and looks upon this outward face of things as upon a mask not worthy to dismay the fixed soul, so the optimist turns away his eyes from the evil which he disposes of as merely negative, as the shadow of the good. Hawthorne's interest in the problem of sin finds little place in Emerson's philosophy. Passion comes not nigh him, and _Faust_ disturbs him with its disagreeableness. Pessimism is to him "the only skepticism."