When will men learn by severe experience that political and religions ideas have conquered more in defence than in offence and aggression, and that reason is the true leader of ideas, and the paths of peace their certain way to victory?

In this one idea then of "black African slavery," as Mr. Seward calls it, we have reached the central fact, or as Abraham Lincoln would say, "the particular spot" upon which sectional parties are staking the destiny of the American Union. All other political questions have sunk to insignificance when compared with this. It would seem as if reckless men were determined that from "this mean and miserable rivulet," are to go out the poisonous waters that shall blast the fair face of this promised land of freedom.

"Slavery agitation, in my opinion," says Abraham Lincoln, "will not cease until a crisis has been reached and passed. 'A house divided against itself cannot stand.'" We are now in the midst of that crisis. It is the pendency of that crisis which has prompted me to address you to-night. For the first time in the history of the government, we have the spectacle of purely sectional parties struggling for the control of the Federal government, each determined to warp and bend to its own sectional end, the Constitution and power of the Federal Union. Never before could patriotic citizens so earnestly lay to heart the counsel of Washington to avoid the formation of sectional parties.

On the 17th of September, 1796, exactly nine years after he, as President of the Convention and Deputy from Virginia, had signed his name to the Federal Constitution, Washington thus addressed his fellow-citizens:

"The unity of government which constitutes you one people is now dear to you. It is justly so; for it is a main pillar in the edifice of your real independence, the support of your tranquillity at home, your peace abroad, of your safety, of your prosperity, of that very liberty which you so highly prize. But as it is easy to foresee that from different causes and from different quarters, much pains will be taken, many artifices employed to weaken in your minds the conviction of this truth—as this is the point in your political fortress against which the batteries of internal and external enemies will be most constantly and actively (though often covertly and insidiously), directed, it is of infinite moment that you should properly estimate the immense value of your National Union to your collective and individual happiness; that you should cherish a cordial, habitual, and immovable attachment to it,—accustoming yourselves to think and speak of it as of the palladium of your political safety and prosperity; watching for its preservation with jealous anxiety; discountenancing whatever may suggest even a suspicion that it can in any event be abandoned; and indignantly frowning upon the first dawning of every attempt to alienate any portion of our country from the rest, or to enfeeble the sacred ties which now link together the various parts."

Fellow-Citizens, the portentous evil which Washington thus deprecated in his Farewell Address to the people of the United States is now upon us. I repeat we are in the midst of the crisis of sectional parties. How shall it be passed, so that the Union shall not fall?

It seems to me that no man who knows our history, who understands truly the genius of our people, and who understands also the principles upon which the Union and the Constitution are based, can fail to believe that it is not by the conflict of sectional parties and their triumph, but by the defeat of sectional parties by a stronger and more patriotic national party, that the divided house can be reconciled and the house itself made to stand in safety. The safety of the Union depends upon maintaining the Federal government in the hands of a national party, which shall carry out the spirit of the Federal Constitution. A solemn responsibility rests upon every citizen in this regard.

I propose then to inquire—

1st—What is the true spirit of the Constitution, and what the true policy of the Federal government on the subject of slavery? and,

2d—How do the parties and the candidates now before the people stand in regard to it?