In today's post, curator Christine Nelson introduces a new blog to accompany the Morgan's exhibition The Diary: Three Centuries of Private Lives, opening on January 21.

We all know that a diary is a private notebook where we write about our days and our thoughts. But is it? As I've explored the many ways we tell the stories of our lives, I've realized how difficult it is to mark the parameters of this intriguing form. Must a diary be private? Must it be written on paper? Must it be written at all? I feel confident that the answer to all these questions is no: many diaries have an audience (real or imagined), many are written outside the traditional notebook, and some take visual form--so what distinguishes a diary from other forms of self-expression? Perhaps it comes down to just two points: the subject of a diary is oneself, and the structure of a diary is incremental, building over time.

But where does a diary end and, say, a sketchbook or scrapbook begin? And what do we call a string of digital updates in which we reveal a little bit each day (or each hour, or each week) about what's on our minds? Or a public blog that tracks our periodic observations? All these forms of self-documentation have something in common with the traditional diary, with its focus on what I thought, felt, read, ate, spent, observed, or did today (and the next day, and the next). In this exhibition blog, I'll be exploring these questions and more, looking closely at some of the extraordinary personal records included in the Morgan's exhibition and inviting guests to discuss the diary in its infinite variety--from everyday logs on paper to real-time life updates in no more than 140 typed characters.

Christine Nelson is Drue Heinz Curator of Literary and Historical Manuscripts at The Morgan Library & Museum and curator of the exhibition The Diary: Three Centuries of Private Lives (January 21-May 22, 2010).