Reputations ebb and flow, leaving little trace of the course they followed in the historical record. Plato (427–347 B.C.) [25] and Aristotle (384–322 B.C.) [8] reign today as giants of Western civilization, but it was a very, very close call for both of them. With the descent of the Dark Ages after the fall of the Roman Empire, the writings of the ancient Greek philosophers were almost lost forever.

People's reputations often change posthumously. Paul Revere (1735–1818) [627] was a silversmith rescued from obscurity by Henry Wadsworth Longfellow's (1807–1882) [349] poem “The Midnight Ride of Paul Revere.” Today, Harriet Beecher Stowe (1811–1896) [449] is far better known than her brother Henry Ward Beecher (1813–1887) [2905], but this wasn't the case during their lifetimes.

There is more to our computational study of history than significance rankings. Here we add another statistical arrow to our quiver. Google Ngrams is an amazing resource for monitoring changes in the cultural Zeitgeist, a dataset that lets us reconstruct how famous someone was 50, 100, or even 200 years ago. In this chapter, we introduce Google Ngrams and present the graphical representations we will use to make proper sense of this data. In particular, we will use it to study the phenomenon of posthumous changes in fame.

Google Ngrams

Scholarly works often include many pages of footnotes, with citations proving that the author has read hundreds of books. Ours doesn't, which might suggest Philistine standards of scholarship.