It was Lincoln who took the aggressive on principles. A famous paragraph of his speech before the convention which nominated him began with the words: "'A house divided against itself cannot stand.' I believe this government cannot endure permanently half slave and half free." That was a direct challenge to Douglas and his whole plan with slavery, and throughout the debate, at every meeting, the doctrine of the divided house was attacked and defended. Douglas declared that Lincoln was inciting half his countrymen to make war upon the other half; that he went for uniformity of domestic institutions everywhere, instead of letting different communities manage their domestic affairs as they chose. But no, Lincoln protested, he was merely for resisting the spread of slavery and putting it in such a state that the public mind would rest in the hope of its ultimate extinction. "But why," cried Douglas, "cannot this government go on as the fathers left it, as it has gone on for more than a century?" Lincoln met him on that ground, and had the better of him in discussing what the fathers meant concerning slavery. They did not mean, he argued, to leave it alone to grow and spread, for they prohibited it in the Northwest Territory, they left the word "slave" out of the Constitution in the hope of a time when there should be no slaves under the flag. Over the true meaning of the Declaration of Independence, however, Douglas had a certain advantage, for Lincoln found the difficulty which candid minds still find in applying the principle of equality to races of unequal strength. Douglas plainly declared that ours is a white man's government. Lincoln admitted such an inferiority in negroes as would forever prevent the two races from living together on terms of perfect social and political equality, and if there must be inequality he was in favor of his own race having the superior place. He could only contend, therefore, for the negro's equality in those rights which are set forth in the Declaration. Douglas made the most of this, and of Lincoln's failure, through a neglect to study the economic character of slavery, to show clearly how the mere restriction of it would lead to its extinction. But Douglas did not, and perhaps he could not, follow Lincoln when he passed from the Declaration and the Constitution to the "higher law," from the question of rights to the question of right and wrong; for there Lincoln rose not merely above Douglas, but above all that sort of politics which both he and Douglas came out of. There, indeed, was the true difference between these men and their causes. Douglas seems to shrink backward into the past, and Lincoln to come nearer and grow larger as he proclaims it: "That is the real issue. That is the issue which will continue in this country when these poor tongues of Judge Douglas and myself shall be silent. It is the eternal struggle between these two principles--right and wrong--throughout the world."