The relations of the Government of the United States—I speak of the National Government—to Slavery, though plain and obvious, are constantly misunderstood. A popular belief at this moment makes Slavery a national institution, and, of course, renders its support a national duty. The extravagance of this error can hardly be surpassed. An institution, which our fathers most carefully omitted to name in the Constitution, which, according to the debates in the Convention, they refused to cover with any ‘sanction,’ and which, at the original organization of the Government, was merely sectional, existing nowhere on the national territory, is now, above all other things, blazoned as national. Its supporters plume themselves as national. The old political parties, while upholding it, claim to be national. A National Whig is simply a Slavery Whig, and a National Democrat is simply a Slavery Democrat, in contradistinction to all who regard Slavery as a sectional institution, within the exclusive control of the States, and with which the nation has nothing to do. As Slavery assumes to be national, so, by an equally strange perversion, Freedom is degraded to be sectional, and all who uphold it, under the national Constitution, share this same epithet. The honest efforts to secure its blessings, everywhere within the jurisdiction of Congress, are scouted as sectional; and this cause, which the founders of our National Government had so much at heart, is called sectionalism. These terms, now belonging to the commonplaces of political speech, are adopted and misapplied by most persons without reflection. But herein is the power of Slavery. According to a curious tradition of the French language, Louis XIV., the grand monarch, by an accidental error of speech, among supple courtiers, changed the gender of a noun; but Slavery has done more. It has changed word for word. It has taught men to say national instead of sectional, and sectional instead of national. Slavery national! Sir, this is all a mistake and absurdity, fit to take a place in some new collection of Vulgar Errors, by some other Sir  Thomas Browne, with the ancient but exploded stories, that the toad had a stone in its head, and that ostriches digest iron. According to the true spirit of the Constitution, and the sentiments of the Fathers, Slavery and not Freedom is sectional, while Freedom and not Slavery is national. On this unanswerable proposition I take my stand, and here commences my argument. The subject presents itself under two principal heads: first, the true relations of the National Government to Slavery, wherein it will appear that there is no national fountain out of which Slavery can be derived, and no national power, under the Constitution, by which it can be supported. Enlightened by this general survey, we shall be prepared to consider, secondly, the true nature of the provision for the rendition of fugitives from service, and herein especially the unconstitutional and offensive legislation of Congress in pursuance thereof. I. And now for the true relations of the National Government to Slavery. These will be readily apparent, if we do not neglect well-established principles. If Slavery be national, if there be any power in the National Government to uphold this institution—as in the recent Slave Act—it must be by virtue of the Constitution. Nor can it be by mere inference, implication, or conjecture. According to the uniform admission of courts and jurists in Europe, again and again promulgated in our country, Slavery can be derived only from clear and special recognition. ‘The state of Slavery,’ said Lord Mansfield, pronouncing judgment in the great case of Somersett, ‘is of such a nature, that it is incapable of being introduced on any reasons moral or political, but only by positive law. It is so odious, that nothing can be suffered to support it but positive law.’ And a slaveholding tribunal,—the Supreme Court of Mississippi,—adopting the same principle, has said:‘Slavery is condemned by reason, and the laws of nature. It exists and can exist only through municipal regulations.’—（Harry v. Decker, Walker R. 42.)And another slave-holding tribunal,—the Supreme Court of Kentucky,— has said:‘We view this as a right existing by positive law of a municipal character, without foundation in the law of nature or the unwritten and common law.’—（Rankin v. Lydia, 2 Marshall, 470.)Of course every power to uphold Slavery must have an origin as distinct as that of Slavery itself. Every presumption must be as strong against  such a power as against Slavery. A power so peculiar and offensive—so hostile to reason—so repugnant to the law of nature and the inborn Rights of Man; which despoils its victims of the fruits of their labor; which substitutes concubinage for marriage; which abrogates the relation of parent and child; which, by a denial of education, abases the intellect, prevents a true knowledge of God, and murders the very soul; which, amidst a plausible physical comfort, degrades man, created in the Divine image, to the level of a beast;--such a power, so eminent, so transcendent, so tyrannical, so unjust, can find no place in any system of Government, unless by virtue of positive sanction. It can spring from no doubtful phrases. It must be declared by unambiguous words, incapable of a double sense.