“Sagacity and eloquence are linked together to such an extent that they cannot be torn asunder for any reason.”

Gitlow v. People of New York, 268 U.S. 652 (1925) (dissenting).
1920s

Very often attributed to Addison, this is in fact by Hugh Blair, published in Blair's Sermons (1815), Vol. 1, pp. 196-197.
Misattributed

Source: Precepts and Judgments (1919), p. 214
Context: The military art is not an accomplishment, an art for dilettante, a sport. You do not make war without reason, without an object, as you would give yourself up to music, painting, hunting, lawn tennis, where there is no great harm done whether you stop altogether or go on, whether you do little or much. Everything in war is linked together, is mutually interdependent, mutually interpenetrating. When you are at war you have no power to act at random. Each operation has a raison d'etre, that is an object; that object, once determined, fixes the nature and the value of the means to be resorted to as well as the use which ought to be made of the forces.

Source: Global Shift (2003) (Fourth Edition), Chapter 2, A New Geo-Economy, p. 19

On Coalition Government (1945)

Letter to John Randolph (1 December 1803), published in The Works of Thomas Jefferson in Twelve Volumes http://oll.libertyfund.org/ToC/0054.php, Federal Edition, Paul Leicester Ford, ed., New York: G. P. Putnam's Sons, 1904, Vol. 109 http://files.libertyfund.org/files/806/0054-10_Bk.pdf, pp. 54
1800s, First Presidential Administration (1801–1805)

Source: Just Listen

Speech in Reply to Senator Stephen Douglas in the Lincoln-Douglas debates http://www.bartleby.com/251/1003.html of the 1858 campaign for the U.S. Senate, at Chicago, Illinois (10 July 1858)
1850s, Lincoln–Douglas debates (1858)
Context: Now, it happens that we meet together once every year, sometimes about the fourth of July, for some reason or other. These fourth of July gatherings I suppose have their uses. … We are now a mighty nation; we are thirty, or about thirty, millions of people, and we own and inhabit about one-fifteenth part of the dry land of the whole earth. We run our memory back over the pages of history for about eighty-two years, and we discover that we were then a very small people in point of numbers, vastly inferior to what we are now, with a vastly less extent of country, with vastly less of everything we deem desirable among men; we look upon the change as exceedingly advantageous to us and to our posterity, and we fix upon something that happened away back, as in some way or other being connected with this rise of prosperity. We find a race of men living in that day whom we claim as our fathers and grandfathers; they were iron men; they fought for the principle that they were contending for; and we understood that by what they then did it has followed that the degree of prosperity which we now enjoy has come to us. We hold this annual celebration to remind ourselves of all the good done in this process of time, of how it was done and who did it, and how we are historically connected with it; and we go from these meetings in better humor with ourselves, we feel more attached the one to the other, and more firmly bound to the country we inhabit. In every way we are better men in the age, and race, and country in which we live, for these celebrations. But after we have done all this we have not yet reached the whole. There is something else connected with it. We have besides these, men descended by blood from our ancestors — among us, perhaps half our people, who are not descendants at all of these men; they are men who have come from Europe — German, Irish, French and Scandinavian — men that have come from Europe themselves, or whose ancestors have come hither and settled here, finding themselves our equals in all things. If they look back through this history to trace their connection with those days by blood, they find they have none, they cannot carry themselves back into that glorious epoch and make themselves feel that they are part of us, but when they look through that old Declaration of Independence, they find that those old men say that "We hold these truths to be self-evident, that all men are created equal" and then they feel that that moral sentiment taught in that day evidences their relation to those men, that it is the father of all moral principle in them, and that they have a right to claim it as though they were blood of the blood, and flesh of the flesh, of the men who wrote that Declaration; and so they are. That is the electric cord in that Declaration that links the hearts of patriotic and liberty-loving men together, that will link those patriotic hearts as long as the love of freedom exists in the minds of men throughout the world.