The following discourses were delivered in Boston, at Hollis-Street Church, on successive Sunday evenings, and repeated at King's Chapel on Monday afternoons, during the winter of 1871-72, in response to an invitation of the Executive Committee of the American Unitarian Association, whose purpose was thus declared in the letter of invitation:—

"It is not proposed that the course shall be a merely popular one, to awaken the indifferent and interest them in familiar religious truths; but rather to meet the need of thoughtful people perplexed amid materialistic and sceptical tendencies of the time. Nor is it desired simply to retrace in controversial method the beaten paths of sectarian or theological debate; but rather, in the interest of a free and enlightened Christianity, to present freshly the positive affirmations of faith."

The several discourses were prepared independently, without conference or concerted plan; and for their statements and opinions the responsibility rests solely with their respective authors.