In 1823, now twenty years of age, Emerson began his studies in theology. Though often attending lectures in Harvard Divinity College he never regularly entered there, but still sat at the feet of Channing, who took a deep personal interest in him. He was "approbated" by the Ministers' Association in 1826. His health having suffered by overwork he passed a winter in the South, and in the following year preached several Sundays at New Bedford, Mass., where he found some friends among the Quakers. He also preached for a time in Concord. In 1829 he was chosen minister of a large congregation in Boston. A venerable minister gave me an account of a sermon he heard from Emerson in those days, impressed on his memory by the vitality it infused in an old theme, and the simplicity with which it was delivered. The text was, "What is a man profited if he shall gain the whole world and lose his own soul?" The emphasis was on the word "own;" and the general theme was, that to every man the great end of existence was the preservation and culture of his individual mind and character. Each man must be saved by his own inward redeemer; and the whole world was for each but a plastic material through which the individual spirit was to realize itself. Aspiration and thought become clear and real only by action and life. If knowledge lead not to action, it passes away, being preserved only on the condition of being used. "The last thing," said my informant, "that any of us who heard him would have predicted of the youth, whose quiet simplicity and piety captivated all, was that he would become the religious revolutionist of America."
And, indeed, so softly did the old religious forms slip away from Emerson, that when he informed his congregation that he could not longer administer the sacrament to them, they could not associate any formidable heresy with his position. They were loath to part with him. In the three years of his ministry he had reflected honor upon their pulpit. He had been active in the philanthropic work of Boston, was chaplain of the Legislature, and on the School Board. A few months after his settlement in Boston he had married Ellen Louisa Tucker and a few months before he gave up his pulpit she died. Under these circumstances of depression Emerson came on his first visit to Europe. The record of his pilgrimage to Coleridge's house at Highgate, to Rydal Mount, and to Craigenputtock, is given in Emerson's "English Traits." He came, hoping to find light upon more serious questions than any that had arisen between him and his Boston congregation; he returned with but one thing made clearer, namely that he had begun an ascent which each must climb alone.