It is commonly agreed by linguists and anthropologists that the majority of languages spoken now around the globe will likely disappear within our lifetime. The phenomenon known as language death has started to accelerate as the world has grown smaller.

This extinction of languages, and the knowledge therein, has no parallel in human history. K. David Harrison's book is the first to focus on the essential question, what is lost when a language dies? What forms of knowledge are embedded in a language's structure and vocabulary? And how harmful is it to humanity that such knowledge is lost...