When I began writing this book I was a philosopher. When an earlier draft was submitted for publication I was a computational linguist. Now I am a company staff scientist. The change in my title did not alter my main professional interests — then, as now, I earn my living working on natural language problems — but the shift in perspectives did bring with it a different sense of my intended audience. It also made me want to prove (first and foremost, to myself) that both philosophy and computational linguistics — even when quite technical — can be made accessible, relevant, and useful for people working on natural language problems in a variety of disciplines Whether I achieved this goal is not for me to say. However, a conceptual map of the book could help readers with different backgrounds identify those segments of the book they may want to concentrate on or, alternately, avoid altogether.