The Vision of Sir Launfal and the Fable for Critics, published in the same year, illustrate the two dominant and strikingly contrasted qualities of his nature, a contrast of opposites which he himself clearly perceived.  “I find myself very curiously compounded of two utterly distinct characters.  One half of me is clear mystic and enthusiast, and the other, humorist,” and he adds that “it would have taken very little to have made a Saint Francis” of him.  It was the Saint Francis of New England, the moral and spiritual enthusiast in Lowell’s nature that produced the poem and gave it power.  Thus we see that notwithstanding its antique style and artificial structure, it was a perfectly direct and spontaneous expression of himself.

The allegory of the Vision is easily interpreted, in its main significance.  There is nothing original in the lesson, the humility of true charity, and it is a common criticism that the moral purpose of the poem is lost sight of in the beautiful nature pictures.  But a knowledge of the events which were commanding Lowell’s attention at this time and quickening his native feelings into purposeful utterance gives to the poem a much deeper significance.  In 1844, when the discussion over the annexation of Texas was going on, he wrote The Present Crisis, a noble appeal to his countrymen to improve and elevate their principles.  During the next four years he was writing editorially for the Standard, the official organ of the Anti-Slavery Society, at the same time he was bringing out the Biglow Papers.  In all these forms of expression he voiced constantly the sentiment of reform, which now filled his heart like a holy zeal.  The national disgrace of slavery rested heavily upon his soul.  He burned with the desire to make God’s justice prevail where man’s justice had failed.  In 1846 he said in a letter, “It seems as if my heart would break in pouring out one glorious song that should be the gospel of Reform, full of consolation and strength to the oppressed, yet falling gently and restoringly as dew on the withered youth-flowers of the oppressor.  That way my madness lies, if any.”  This passionate yearning for reform is embodied poetically in the Vision.  In a broad sense, therefore, the poem is an expression of ideal democracy, in which equality, sympathy, and a sense of the common brotherhood of man are the basis of all ethical actions and standards.  It is the Christ-like conception of human society that is always so alluring in the poetry and so discouraging in the prose of life.

The following explanation appeared in the early editions of the poem as an introductory note: