The fact exists that there is a war between the North and South, brought about, as we believe, by unwarranted and aggressive acts of the Slave Power. This slave oligarchy of the South either had, or affected to have, a profound contempt for what they supposed was the want of spirit in the Northern people. It was a current swagger that we should barely furnish them with an opportunity to show their superior military prowess. 'This war shall be waged on Northern soil,' they said. Events have shown that they miscalculated; but the raids of Jackson, Lee, Morgan & Co. show how great their will has been to carry out their threats of invasion. When the rebel guns opened upon Sumter, there was no alternative left us but fight now, or soon. Had we hesitated and compromised then, the arrogant spirit of the insurgents would have been still further flattered and puffed up, and their contempt for the submissive North made genuine, whatever it may have been before. A compromise then would have made no lasting peace; the South would soon have become tired of being merely 'let alone;' her exactions and aggressions would have become more and more insolent and intolerable, till warlike resistance or ignoble submission and slavery would have been our only alternative. This war is, therefore, on our part and in one sense, a war in self-defence; and this may be regarded as one of its issues. Every loyal soldier is fighting for the security of our Northern homes; and the issue resolves itself into this: The resistance of invasion; the vindication of our manliness as a people; the protection of our own firesides--else be overrun, outraged, desolated, enslaved by the minions of a Southern oligarchy, which indulges the insane conceit that it is born to rule. * * * * * Unfortunately for our country, it embraces two distinct forms of society, of dissimilar, if not of antagonistic character. It is a heritage from our ancestors; but none the less an evil for its prestige from the sanctities of time; and we are now reaping its bitter fruits in the manifold and hideous forms of a great civil war. Taking human nature as it is, there appears to be no escape from this cruel ordeal. We of the North claim that we have transcended that type of society whose vital and informing element is chattel slavery. There is natural and irrepressible antagonism between the two forms of society; they cannot subsist in peace and good feeling by the side of each other, and still less under the same Government. Conflict was inevitable, and it came. At this stage of the war and of elucidation respecting its cause and origin, this may be only commonplace, yet necessary to fulness of statement.