"History" imparts an uplifting, optimistic mood to the reader. Emerson writes the essay as if he is trying to inspire the reader, to goad them into conducting the great work of history for themselves:
Broader and deeper we must write our annals,—from an ethical reformation, from an influx of the ever new, ever sanative conscience,—if we would trulier express our central and wide-related nature, instead of this old chronology of selfishness and pride to which we have too long lent our eyes.
Emerson has no illusions about the negative potential of humanity's self-serving side, but he fervently believes in the inherent goodness of humankind, and writes this essay in defense of that—and in the belief that, going forward, we can conduct better historiography out of this goodness.
Both transcendentalism and Unitarianism—the main philosophical and religious movements with which Emerson aligned—centered on the empowerment of the individual to identify and appreciate the inherent unity of all nature. Emerson's optimism in "History" therefore reflects the reality that both movements could only succeed if they were able to successfully inspire the individuals they so revered—which is to say, the individuals who comprise the population at large, adherents and skeptics alike—to feel empowered to take up the cause and effect social change.
