PEYSER: Was there a particular moment when you decided to leave “Spin City”? FOX: I was in St. John’s on vacation this winter, and my son and I wanted to find some sea turtles. So we put on our snorkel gear and went out. Eventually I found one and just followed it around for about 45 minutes. And when I came back to the beach, and I put my snorkel down, I said, “I’m done.” I hadn’t felt that good in such a long time. I’d been finding over the last few years that my symptoms were milder on vacations. Without the stress, I was just having an easier time of it. In order to do the show I have to be gussied up with medication. Plus, I just didn’t feel I had the energy, especially given that I have an opportunity to help in the fight against Parkinson’s. I wanted to have some energy for that.

You’ve never been one of those politically active Hollywood types. What made you decide to get involved now? Going down to Washington last year was a real eye-opener. I was with Joan Samuelson, the founder of the Parkinson’s Action Network. We testified before Arlen Specter in the Senate about appropriating NIH money for Parkinson’s. And afterwards we were walking through the halls, and Joan was literally weeping. And I’m thinking, What are you weeping about? We’re having a great time–you know, I never thought I’d be speaking to Trent Lott. Then I realized: the Parkinson’s people had never had anybody to help them get the attention.

And now you’re starting your own Parkinson’s foundation. What is it called? It’s called, under some protest from me, the Michael J. Fox Foundation for Parkinson’s Research. The fact that it’s eponymous just freaks me out. But I understand, from a branding point of view, that it’s effective. I get e-mail from people all the time saying, “I finally told a co-worker that I had Parkinson’s, the Michael Fox disease.” That’s pretty heavy.

How has the disease limited you physically? It depends on the way I’m medicated at the time. Like right now, I could do just about anything. I still ice-skate and ski. But it takes 10 times more energy for me to walk across the room than it does for you. From an acting point of view, it’s really been kind of interesting, and I think it resulted in some great work. Before my illness, I wasn’t ever thinking about acting when I was doing it. Now, I’m always thinking, “How am I going to do this today and be funny?” It was an interesting set of puzzles to solve.

What about with your kids? Can you do all the Dad things with them? My twin daughters are 5. They’re oblivious. They think that I could climb the Empire State Building. There are times when I may not get up and run around. They’ll come up to me with the hair clips in the morning, or the hairbrush. And I just go, ‘Hey, I don’t do hair in the morning.’ I would never say to them, “Daddy can’t do that now.’ But no matter how bad my dexterity may be at a given moment, I can always haul one of them up on my shoulder. So you roll with it. It’s like everything–you just roll with it. My son is 11. When I had my brain surgery a couple years ago, he was of an age when obviously I had to have a conversation, and say, “I’m going to do this thing. I feel like I’m going to be OK. But please tell me if you have concerns about it.” And he didn’t–he was great. There’s a story that was a really great moment for me. I was talking to my son one day, and he was looking me in the eye, and we were really engaged, and we were having this conversation. At the same time, my hand was doing this [he shakes his left hand vigorously]. And instead of breaking the conversation, he just reached out, put his hand on my hand, and we just kept talking.

Other than raising Parkinson’s money, what plans do you have for the future? Will you act again? Absolutely. I will keep acting, as things come up, and producing. But right now, I just want to focus on this and kind of lay back. I think at some point I may write a book. I’m as jaded about celebrity memoirs as everybody else is, so that’s not what I want to do. Someone was asking me the other day, what would I write? And I said, “How to lose your brain without losing your mind.”