PW: You've written two historical cookbooks, Shakespeare's Kitchen and now The Philosopher's Kitchen. What's your background?

I was a child psychologist who loved cooking, but I didn't like following a cookbook. I liked research. I would do dinner parties with things like the food Casanova wrote about in his memoirs, or 2,000 years of Sicilian cooking. Then a friend was performing Shakespeare one summer up in Williamstown [Mass.], and he asked me to do a Shakespeare dinner, which got me obsessed. Some friends encouraged me and told me that this could be a book. When Random House bought that book, my editor asked if I had some other ideas, and during the Renaissance people were in love with the ancient Greeks. So that book led to this one.

Why'd you choose to "update" these recipes?

When I was working on Shakespeare's Kitchen, I would make a recipe "straight," and then I would say, "If we just...." For example, there was a recipe for duck with gooseberry sauce, but they boiled the duck. I thought the taste was really great, but you had to be eating by dim candlelight—it was all white. I wondered, would it be cheating if I braised it or pan-fried it? And my editor said, "You're not re-creating a room at the Metropolitan Museum of Art." Once I got that liberating permission, I realized I could tweak it so it tastes a little better and is easier for us. I can use a blender instead of a bunch of twigs bound with a cord.

What foods do we eat today that are exactly as they were in the Greek and Roman eras?

Minted Garlic Spread is kind of a classic dish in Greek restaurants as one of the mezze things. There's also Cato's Herbed Olive Purée. His job was being a politician, but then he bought this farm and wrote a book called On Agriculture, including recipes, and it's got this great recipe for a classic thing I thought was French.

Were the ancient Greeks and Romans as obsessive about food as we are, or did they just eat to survive?

More than we do, what they ate they tied totally to their health and personality. Food was way more than just a meal. It was a way to control your health, cure yourself and change things like personality. Hippocrates talked about how if you want to be less big, you should eat foods rich in protein, like meat, because you'll crave less. That's the South Beach Diet! There's nothing new.

Are there any special marketing plans for the book?

Since this summer the Olympics will be held in Greece, I was asked by TheTodayShow to do a spot on some of the food they would have eaten back then. That will be on in August during the Olympics. Some athletes ate raw food only, which I thought was a California modern thing.

So, if we didn't invent the low-carb diet or the raw foods movement, what do we eat today that would horrify someone from those times?

It sounds pedestrian, but I think about how horrified they would be to see we're 2,000 years into the future, and we've gone backwards. We're eating less things—less body parts, less herbs. But they would be amazed at microwaves and ovens with dials. They spend a lot of time talking about getting the oven right.