It is asked, said Henry Clay, on a memorable occasion, Will slavery never come to an end? That question, said he, was asked fifty years ago, and it has been answered by fifty years of unprecedented prosperity. Spite of the eloquence of the earnest Abolitionists,--poured out against slavery during thirty years,--even they must confess, that, in all the probabilities of the case, that system of barbarism would have continued its horrors far beyond the limits of the nineteenth century but for the Rebellion, and perhaps only have disappeared at last in a fiery conflict, even more fierce and bloody than that which has now been suppressed. It is no disparagement to truth, that it can only prevail where reason prevails. War begins where reason ends. The thing worse than rebellion is the thing that causes rebellion. What that thing is, we have been taught to our cost. It remains now to be seen whether we have the needed courage to have that cause entirely removed from the Republic. At any rate, to this grand work of national regeneration and entire purification Congress must now address itself, with full purpose that the work shall this time be thoroughly done. The deadly upas, root and branch, leaf and fibre, body and sap, must be utterly destroyed. The country is evidently not in a condition to listen patiently to pleas for postponement, however plausible, nor will it permit the responsibility to be shifted to other shoulders. Authority and power are here commensurate with the duty imposed. There are no cloud-flung shadows to obscure the way. Truth shines with brighter light and intenser heat at every moment, and a country torn and rent and bleeding implores relief from its distress and agony.