It is my solemn and responsible duty to bring before you to-night the _principles_ and _measures_ of a large, respectable, and powerful body in the United States, known by the name of IMMEDIATE ABOLITIONISTS. A body of individuals embracing not fewer than fifteen hundred ministers of the gospel, and men of the highest station and largest attainments. A body of persons that have been charged upon this platform with being a handful, "so small that they could not obtain their object, and so erroneous (_despicable_ was, I believe, the word used) as not to deserve success,"--charged with being the enemies of the slave-holder--taking him by the throat, and saying "you great thieving, man-stealing villain, unless you instantly give your slaves liberty, I will pitch you out of this third-story window,"--charged with carrying in their track a pestilence like a storm of fire and brimstone from hell; forcing ministers of religion to seek peaceful villages not yet blasted by it,--charged with saying that they were sent from God, when they possessed the fury of demons,--charged, finally, with having "thrown the cause" of emancipation "a _hundred years_ farther back than it was five years ago." These are fearful indictments, and Mr. Breckinridge has a weighty duty to fulfil to-night, for he is bound to sustain them. They have been brought by himself, a Christian minister, the professed friend of the slave; and he must, therefore, abundantly support them by incontrovertible evidence, or stand branded before the world as the worst foe of human freedom--the foul calumniator of the friends and advocates of the oppressed, the suffering, and the dumb. He would lay the principles of the American abolitionists before the audience in the words of their solemn and official documents. He would go back to the commencement of the five years mentioned by his opponent, and read from the "CONSTITUTION of the NEW-ENGLAND ANTI-SLAVERY SOCIETY," a lucid exposition of the principles and objects of the first Anti-Slavery Society (technically so called) in the United States. "We, the undersigned, hold that every person of full age and sane mind, has a right to immediate freedom from personal bondage of whatsoever kind, unless imposed by the sentence of the law for the commission of some crime. We hold that man cannot, consistently with reason, religion, and the eternal and immutable principles of justice, be the property of man. We hold that whoever retains his fellow man in bondage, is guilty of a grevious wrong. We hold that a mere difference of complexion is no reason why any man should be deprived of any of his natural rights, or subjected to any political disability.