Observations on teaching and textbook writing

During a career spanning several decades, I have often reflected on the relationship between teaching and textbook writing. Indeed, in my experience, every successful textbook author I have met or read about has always been a very accomplished—often a prize-winning—teacher. The reverse does not seem to be the case, however. I know of excellent teachers whose textbooks never gained traction. And there are thousands of great teachers who do not have the slightest interest in writing a textbook. (I too never aspired to textbook authorship until a publisher approached me about becoming the junior author of the leading introductory art history textbook. I eventually consented because I found enormously appealing the prospect of extending my teaching nationwide and reaching tens of thousands instead of hundreds of students every year.)