We still know so little about how the brain interacts with the body chemistry or, for that matter, whether we should be talking about the brain or the mind, that it would be perilous to hazard any guess about the way Abraham Lincoln's biological health may or may not have affected him. Of course, we don't have Lincoln on hand to ask him directly; but even if we did, we still might not be able to make sense of how all the parts worked together.

Until the early 90s, when I was working on a project about the idea of free will in American philosophy. I knew that Lincoln had had something to say about "necessity" and "fatalism," and so I began writing him into the book. In fact, Lincoln took over. I wrote instead 'Abraham Lincoln: Redeemer President,' in 1999, and I've splitting rails with Mr. Lincoln ever since. If there's a twelve-step process for this somewhere, I haven't found it yet.

Corporate organization in American business and commerce was already well under way by the time Abraham Lincoln became president. But all the evidence from his pre-war lawyering days is that he had little objection to the rise of corporations. As a state legislator, he had strongly favored the creation of an Illinois state bank, as well as sponsoring the chartering of public/private corporations like the Illinois Central Railroad.

Abraham Lincoln did have intellectual instincts, a tremendous curiosity on a broad range of subjects, and a near-photographic memory for what he read. He was, at the end of the day, a politician: politics were his heaven, said William Herndon. But Lincoln did take comfort in ideas and books, more so than almost any other president, and he went to books and ideas in moments of perplexity to sort things out. Philosopher, no, but thoughtful and "surprisingly well-read" for his day.

No one loves an archive better than I do. I can smell a good one half-a-block away - all that brittle papyrus dust is music to my nostrils.

I suspect, too, that the modern debates represent the effort of candidates with widely-varying constituencies and special interests to please to tip the hat as quickly as possible to as many of the constituencies and interests as possible. That leaves no time for big-picture issues. Contrast this with Abraham Lincoln and Stephen A. Douglas, where the subject was only ever slavery, and the discussion went right to the bedrock of what a democracy is all about.

I don't know that there has ever been a time when Abraham Lincoln didn't stand head-and-shoulders above all other presidents in the historians' eye. But relatively speaking, there have been peaks and a troughs. One peak was in the 1910s-20s; a major trough was in the 1970s-80s. We are certainly on a peak again, something which began in 1994 with Michael Burlingame's 'The Inner World of Abraham Lincoln,' which showed in fabulous detail how many new and untapped sources were available on Lincoln.