When Ralph Waldo Emerson mounted the pulpit in Cambridge’s First Parish Church on August 31, his audience expected to hear the usual Phi Beta Kappa address given the day after every Harvard commencement—another rendition on the topic of the American scholar. For decades it had been squeezed and wrung for all it was worth. But that day Emerson gave new life to it.

Oliver Wendell Holmes later called the speech “our intellectual Declaration of Independence,” for in it Emerson urged his countrymen to cast off their “long apprenticeship to the learning of other lands.” Emerson, however, wished to do more than foster literary nationalism. His subject was not just the American scholar, in fact, but what he called “Man Thinking.” He wished each generation everywhere to free itself from the bonds of tradition and do its own thinking. “If the single man plant himself indomitably on his instincts and there abide,” he said, “the huge world will come round him.” For every mind is an extension of the Divine Mind, and in every particular truth can be found the greater one: “Give me insight into today, and you may have the antique and future worlds. What would we really know the meaning of? The meal in the firkin; the milk in the pan; the ballad in the street; the news of the boat; the glance of the eye; the form and the gait of the body … let me see every trifle bristling with the polarity that ranges it instantly on an eternal law; and the shop, the plow, and the ledger referred to the like cause by which light undulates and poets sing … one design unites and animates the farthest pinnacle and the lowest trench.”

Not everyone understood what Emerson was talking about. The address “was to me in the misty, dreamy, unintelligible style of Swedenborg, Coleridge, and Carlyle,” wrote Rev. John Pierce, a chronicler of Harvard’s anniversaries. The author and minister Edward Everett Hale later wrote: “I remember how afterwards men and women freely said he was crazy.”

But the speech caused at least one prominent voice to sing Emerson’s praise. When a copy of “The American Scholar” reached Thomas Carlyle in England, he wrote to Emerson: “Lo, out of the West comes a clear utterance, clearly recognisable as a man’s voice, and I have a kinsman and a brother: God be thanked for it! I could have wept to read that speech. … My brave Emerson! … May God grant you strength, for you have a fearful work to do!”