It may appear somewhat inexplicable to those who have not maturely considered the subject, that the people of the South should with so much seeming suddenness maintain the propriety of an energetic plan of resistance to Northern aggression even to the severance of the Union. There are persons who fail to perceive why the South, which, prior to the Presidential election, was by no means unanimously of opinion that the election of LINCOLN should be regarded as a legitimate cause for disunion, should now be almost universally in favor of proceeding to the last extremities in defense of her rights. A little reflection, however, will make this matter clear and intelligible.

During the recent Presidential canvass the South was buoyed up with the hope of defeating Black Republicanism. The assurances of the Northern national men had had the effect of persuading even against their better judgment a large number of our citizens that the cause of the South was not desperate, and that it was sustained at the North by a popular strength sufficient to overthrow Black Republicanism and its hosts. Impressed with this idea, it was entirely natural for the South to cling to the hope of preserving the Union. Believing either that LINCOLN would be beaten, or that even if chosen, his success would be a bare and barren victory, due rather to the dissensions of his competitors than to the popularity of his cause, the people of the South did not and could not anticipate the overwhelming antislavery demonstration which tools place on the 6th of November last. It may be safely said that when they spoke of acquiescing in the election of LINCOLN, they either thought such a result highly improbable, or imagined that if it did occur, he would be so evidently the choice of a slender minority as to dispel all apprehensions of future danger from his administration.

But the result proved astounding. It showed the tremendous power and popularity of Black Republicanism. That dogma has carried every non-slaveholding State in the Union for LINCOLN; New Jersey itself, which was at first thought against him, having given him four out of seven electoral votes; while both California and Oregon—States in which it had been confidently believed Abolitionism had no local habitation—have pronounced in his behalf. The thousands of Southern citizens who had honestly and sincerely imagined Black Republicanism to be far less potent, stood aghast at these developments. The facts and figures of the Presidential election, as they came gradually to be known, sapped, destroyed and annihilated their long cherished sentiments of nationality. What could be alleged against such convincing and irrefragable proof of Northern unsoundness? With what shadow of reason could Southern men be advised to submit and await the possible events of the future when Abolitionism had swept every Northern commonwealth, and had even displayed unexpected and growing power in some of the slaveholding States themselves? Hence it is that but a few days had elapsed from the announcement of the result when, to the astonishment of many, the former strongest advocates of union and conservatism were found battling in the front ranks of Southern rights and secession.

There are circumstances connected with the election of LINCOLN which may not strike the casual reader, and yet to the reflecting mind are cogent evidences of a state of public opinion in the North eminently unfavorable to the prospect of a harmonious adjustment of difficulties. One of these points has been alluded to by Dr. PALMER in his masterly discourse on Thanksgiving Day. He observed, in speaking of the improbability of obtaining effective guarantees from the North, that the people of that section were, almost to a man, antislavery when they are not abolition. “A whole generation,” said he, “has been educated to look upon the system of slavery with abhorrence as a national blot. They hope and look, and pray for its extinction within a reasonable time, and cannot be satisfied unless things are seen drawing to that conclusion. We, on the contrary, as its constituted guardian, can demand nothing less than that it should be left open to expansion, subject to no limitations save those of GOD and nature. I fear the antagonism is too great, and the conscience of both parties too deeply implicated, to allow such a composition of the strife.” We may add that it is precisely this fear which haunts the minds of the citizens of the cotton States, and which has identified so many of them with the revolutionary movements of the day. It is not the naked fact of LINCOLN’s election. That might have been tolerated, because it might have been the product of an accident, a mere slipping in of a candidate of one party running against three representatives of another party. It might have represented all the symptoms of a fortuitous and transitory misfortune, which the South might have accepted without repining, simply because it offered no peril for the future. But as it stands the Black Republican victory of November is the incontrovertible proof of a diseased and dangerous public opinion all over the North, and a certain forerunner of further and more atrocious aggression. Moderate men, therefore—good men—men who have heretofore clung steadfastly to the Union, believed in its perpetuity, and discountenanced even a thought of its dissolution, are now forced painfully, reluctantly, with sorrow and anguish, to the conclusion that it is wholly impossible for the South tamely to tolerate the present, or indulge the slightest hope of an improvement in the future. They now see clearly that there are but two alternatives before the South, provided she is not insensible to dishonor and disgrace—either a final separation from the section which has oppressed and aggrieved her, or a new compact under which her rights will be amply secured. The one may take place, and still eventually prepare for the other.