Finding the Thinkable Thoughts

When John B. West developed his legal classification system in the 1880s, he likely didn’t anticipate that his system of indexing the law would persist into the twenty-first century. But persist it has, and flourished, most prominently in the form of Westlaw’s headnote and key number system. West’s index built on several precursors, but it was his version, West’s American Digest, that established the foundations of the classification system that most modern legal researchers use today, in one form or another. This history—of the late-nineteenth-century fascination with indexing—and much more is told in charming detail in Dennis Duncan’s Index, A History of the. Anyone interested in how we classify, find, and use information is likely to be intrigued by the book’s recounting of the life of this tool. The index is nearly ubiquitous in non-fiction materials today, yet we tend to take for granted what a remarkable tool it is. And that includes, of course, lawyers and other legal researchers. While the book does not address legal indexes specifically, its discussion of the history, purposes, and substance of the index calls to mind modern legal indexes like Westlaw’s headnote and key number system.