You’ve got to check out the Google Ngram Viewer. It allows you to tabulate, in the form of a graph, the number of times a word or phrase is mentioned in the vast number of titles in Google Books, from 1500-2000. Those periods of time are statistically evened out, so that the far greater number of titles available in the last few decades does not overwhelm the relatively fewer number of titles in earlier centuries.
This allows users to explore trends in the history of ideas, language, and culture. For example, go to the linked site and type in “Christ.” (Note the decline.) “Boredom.” (Was no one bored until the modern era?) Do a comparison by typing in two terms: Try “reason” and “culture.” (Notice how “culture” hardly existed as a concept until a few decades ago, but now it has passed “reason,” which had its heyday just after the Enlightenment, as we would expect. This might make us wonder how long “culture” will last.)
At the site read “About Google Books NGram Viewer” to see what all else it will do. (It can be narrowed down in some very useful ways.)
Play around with it and post your discoveries here.