We are now far into the fifth year since a policy was initiated with the avowed object and confident promise of putting an end to slavery agitation. Under the operation of that policy, that agitation has not only not ceased but has constantly augmented. In my opinion, it will not cease until a crisis shall have been reached and passed. "A house divided against itself cannot stand." I believe this government cannot endure, permanently, half slave and half free. I do not expect the Union to be dissolved; I do not expect the house to fall; but I do expect it will cease to be divided. It will become all one thing, or all the other. Either the opponents of slavery will arrest the further spread of it and place it where the public mind shall rest in the belief that it is in the course of ultimate extinction, or its advocates will push it forward till it shall become alike lawful in all the states, old as well as new, North as well as South. (3-10)

The first paragraph of this speech is really the only part anyone regularly remembers. But that's because this part is really, really, really good and the rest is only really, really good. Lincoln addresses the Republican convention, and immediately directs the audience's attention to the big issue of the day: the potential expansion of slavery.

To do that, he first points out that there has been a policy in place for several years (popular sovereignty) that was supposed to calm everyone down, but has just made everything worse. As a result, the country is divided like nobody's business. Lincoln argues that the country can't keep on keeping on this way—it's going to have to come down on one side or the other, or the union between the states will fail. He assures the audience that he doesn't think the union will fail—but the bad news is that could mean that slavery will exist ev-er-y-where.

This opening paragraph sets up the motivation for Lincoln's speech, as well as the central metaphor. He presents the current America in a way that threatens his audience's way of life, but leaves a glimmer of hope that something can be done to save it. The "house divided" metaphor works well for his purpose; after all, we all know what a house is, and odds are we've all been to one of those family dinner parties that makes you question why people have family dinner parties.

To this day, people reference the metaphor when talking about a group of people who are supposed to be united facing serious division.