Fifteen billion printed words from 5.2 million books, or 4 percent of all books published! Graphed and searchable! Thank you, Google! Thank you, Harvard!

Why am I ecstatic? The project, reported in the journal Science yesterday and available for the use of all, at once creates a new tool for cultural history (dubbed “Culturomics”) and vastly facilitates one of the oldest (known in German as Begriffsgeschichte, or the history of concepts). Type in a word or phrase along with the dates you want, and you get a graph showing the percentage of its appearances in books printed at a given time. Click on the time period, and you get a Google catalog of the actual appearances, with access to the texts themselves.

This allows us both to assess the cultural impact of major concepts and figures over time, and  to trace and analyze with precision the incidence and significance of lesser concepts and figures. The results can confirm or disconfirm general ideas about cultural history as well as suggesting new areas of inquiry. They also make it possible to clarify with almost alarming speed our understanding of how specific ideas and concepts came to the fore, and in what context. In the realm of big religious categories, consider the following:

Christian: It peaks in the early 16th century when the Reformation is in full throttle; bounces around from the late 16th through the 17th during the Wars of Religion; sinks to low ebb during the 18th-century Enlightenment; makes a major recovery in the first half of the 19th century (i.e. the Second Great Awakening); thence declines until the latter part of 20th century (with a bump up for the “Eisenhower Revival”); and now seems to be on the rise again. Pretty much what you’d expect.

Protestant: The big peak comes during the English Civil Wars of the 1640s. Thereafter, it hits a high point in 1850, sinks steadily into the 1930s, and has held pretty constant since. Again, to be expected.

Islam: Steady growth over the past century, but why does the biggest jump come in the 1950s? And why the decline since 9/11?

Atheism: The recent bump of interest is no surprise, but the real interest in the subject begins with the French Revolution, and persists through the revival of the 19th century. Call it evidence of the War Between Science and Religion.

Judaism: There’s a steady rise from the beginning of the 19th through the end of the 20th centuries, with fin-de-siecle bumps, perhaps relating to (1) immigration and (2) Holocaust studies. But since 1996 there’s been a notable decline. How come? Secularism shows a remarkable parallel: steady rise through the 20th century with a turnaround in 1996. Correlation or coincidence? (Update: Holocaust and Shoah both peak in 1999.)

This is, of course, the merest soupcon of how the database can be used. I’ll have more to say about it anon.