PW: What inspired you to write Mosque? Did the events of September 11 contribute?

David Macaulay: September 11 was a Tuesday, and I called Walter [Lorraine, Macaulay's longtime editor at Houghton Mifflin] on Saturday. I said, "I think I have to do Mosque. I know I have to do something." I was just beginning this huge project on the human body, but I had to stop and change directions.

PW: What kind of research did you do for the book?

DM: I'd been to Turkey as a student way back in '68, but it hadn't resonated with me the way that classical Roman architecture had. Then I returned a few years ago while filming Building Big, and I thought, "This is great!" But I put it away again, buried it in the back of my head until September 11.

For Mosque, I went back to Istanbul and spent a week going from mosque to mosque—the small ones, not the big ones. I worked with local people. I met an engineer at the technical university for tea, for instance, and just picked his brain mercilessly, and I also spent time with a family of architects involved in restoring mosques around Turkey. They were wonderful, and had actually written a book full of first-hand accounts of work done on the job.

I also met a filmmaker who gave me a copy of his film about Sinan—architect to the Sultan for 50 years—who really created what we think of as Ottoman architecture. I had a level of research that I'd never had before, and it was terrific.

PW: This is the first of your books in this series in full-color. Why?

DM: It had to be because of the interiors. It's impossible to step into an Ottoman mosque and not be knocked out by the elaborate tile work and paint. Also, 25 years ago, using color in a picture book was an important economic constraint, but that is no longer the case.

PW: In what ways does your architectural training influence the way you approach a book like Mosque, or, before that, Cathedral, Castle and Building Big? Do you begin with the drawings and then move to the text? From the text and move to the illustrations? Or do they develop concurrently?

DM: As an architectural student, you learn how to dismantle complicated things, break them down into pieces that you interpret and try to understand in order to solve a problem.

When I'm given a building like a small mosque or cathedral, the problems have already been solved, and my job is to reconstruct the problems and re-present them as I show the building growing. Around me right now, I have four models of mosques in partial states of disarray—I built them in order to take them apart and understand the sequence of construction, the geometry from the ground up. You can only get so much from elevations, and I need to see that what I'm reducing to two-dimensional form is on the right track. So I construct both verbally and visually right from the beginning.

PW: What do you think such awe-inspiring structures say about the people who build them? What do you think such monuments do for people and society?

DM: One of the obvious things they do is give the satisfaction of having left something permanent behind. As a society, there's the reassurance of linking yourself with some higher thoughts and a higher being, that seems to have a remarkable power in getting people to do things they might not otherwise have thought they could do. So they satisfy some very basic human needs, from personal and civic pride to paying the rent, but also go beyond that to satisfy some less tangible human need.

PW: What was your goal for the book?

DM: The goal was to simply have a book about Islamic architecture on school and library bookshelves next to Castle and Cathedral. I wish it had been there 20 years ago, but I didn't do it and no one else did it, either. I got a chance to make up for that oversight.

The nice thing about having Mosque and Cathedral side by side on the shelf is that you see they are not dissimilar in their objectives, really. Both are attempts to create the ideal space for the specific needs of a religion, and the much broader needs of a society trying to connect with God and heaven. The books are in a sense less about the differences between people than they are about the similarities.

PW: What are you working on now?

DM: I'm back at work on the human body book. Right now I'm surrounded by photographs of dissected hands! My goal is to build a body—I want to know how all the pieces go together and what they do. For two years, this will be my sole focus, and we'll see if I can pull it off. I've never been quite so out of my depth before, and happy to admit it. I don't necessarily know a lot about my subjects when I start, but in this case, I know nothing. Could there be a better job?