One of the pleasures of my job is tormenting—or at least trying to torment—my friend and colleague Marc Peyser,our arts editor. Marc is a brilliant man, a keen writer and a gifted editor, but he also has a strong streak of Charlie Brown in him. He always anticipates the worst and believes the end of all things is just around the corner. You know the type: if he won the lottery, he would immediately start fretting about the tax hit.

In our work together, this "Hoo-Boy" personality manifests itself in ways like this: a few months ago, when we were discussing this week's cover, our second annual Global Literacy project, Marc told us that Malcolm Jones had just volunteered an interesting factoid: both Abraham Lincoln and Charles Darwin were born on the same day in 1809, and were thus about to mark their bicentennials. What about a little essay, Marc said, on the two men?

For me, the idea was like Christmas in May: two towering figures who had shaped the way we live now, redefining politics and science and philosophy and—well, just about everything else, too. A cover, I thought, that's the cover—Lincoln vs. Darwin: Who Mattered More? They are venerated figures (and, in Darwin's case, much maligned), men whose examples still inspire and instruct. Not a few politicians have sought solace in the image of Lincoln's struggle to save the Union; not a few scientists and philosophers have found a model in Darwin's intellectual curiosity and devotion to data. What links them for our purposes is that they are essential elements of the story of the world we inhabit. (If you want to get technical about it, you can raise the reasonable point that it is an unanswerable question, but that's no fun. We do hazard an answer, and expect a lot of you to disagree—which is, in a way, one of the points of the exercise.)

Ordinarily, when an editor here suggests something that gains momentum and wins enthusiastic plaudits internally, that editor is pleased. But not Marc. Having solved all our problems with a terrific insight, armed with Malcolm, a great writer, to execute it, Marc set out to sabotage his own idea. You won't really want that, he said, then tried another tack: there's not much to say. Neither turned out to be true, and despite Marc's best efforts, his idea is the centerpiece of the project. You are the beneficiaries of his and Malcolm's brilliance, and you did not even have to deal with the cries of "Good grief!" wafting down the halls.

We started our "What You Need to Know" series in 2007 on the ground that there is some utility in our holding some common ideas and views—or at least in debating the same ideas and views. As you will see, our series of essay questions is arbitrary and eclectic, but then so is life. The diversity of topics suggests that the more narrowly defined cultural-literacy exercises of two decades ago are perhaps obsolete. Beginning with Marc and Malcolm's good suggestion about Lincoln and Darwin, the list is mostly the result of conversations between our editors and writers to identify some, but not all, of the ideas, big and small, that are worth debating or at least knowing about in an epic election year.

I am grateful to Mark Miller(who works closely with Charlie Brown—er, Marc Peyser) for his stewardship of the project, which includes essays from Evan Thomas, Jonathan Darman, Steve Tuttle, Lisa Miller, Stuart Taylor Jr., Fareed Zakaria, Sharon Begley, N'Gai Croal, Daniel Gross, Jerry Adler, Lorraine Ali, David Ansen, Tony Dokoupil, Cathleen McGuiganandJoshua Alston. Dan Revitte designed the package.

This is our July 4 double issue; in the interim, we will see you online every day at Newsweek.com, and again in print on Monday, July 14.

© 2008