Among nations, no one has more need of full knowledge of itself than the United States, and no one has hitherto had less. It has hardly had a distinct consciousness of its own national existence, and has lived the irreflective life of the child, with no severe trial, till the recent rebellion, to throw it back on itself and compel it to reflect on its own constitution, its own separate existence, individuality, tendencies, and end. The defection of the slaveholding States, and the fearful struggle that has followed for national unity and integrity, have brought it at once to a distinct recognition of itself, and forced it to pass from thoughtless, careless, heedless, reckless adolescence to grave and reflecting manhood. The nation has been suddenly compelled to study itself, and henceforth must act from reflection, understanding, science, statesmanship, not from instinct, impulse, passion, or caprice, knowing well what it does, and wherefore it does it. The change which four years of civil war have wrought in the nation is great, and is sure to give it the seriousness, the gravity, the dignity, the manliness it has heretofore lacked. Though the nation has been brought to a consciousness of its own existence, it has not, even yet, attained to a full and clear understanding of its own national constitution. Its vision is still obscured by the floating mists of its earlier morning, and its judgment rendered indistinct and indecisive by the wild theories and fancies of its childhood. The national mind has been quickened, the national heart has been opened, the national disposition prepared, but there remains the important work of dissipating the mists that still linger, of brushing away these wild theories and fancies, and of enabling it to form a clear and intelligent judgment of itself, and a true and just appreciation of its own constitution tendencies,--and destiny; or, in other words, of enabling the nation to understand its own idea, and the means of its actualization in space and time.