The most common objection that I hear to walking as exercise is that it's too easy, that only sweaty, strenuous activity offers real benefits. But there is abundant evidence that regular, brisk walking is associated with better health, including lower blood pressure, better moods and improved cholesterol ratios.

Whenever the immune system deals successfully with an infection, it emerges from the experience stronger and better able to confront similar threats in the future. Our immune system develops in combat. If, at the first sign of infection, you always jump in with antibiotics, you do not give the immune system a chance to grow stronger.

Massage therapy has been shown to relieve depression, especially in people who have chronic fatigue syndrome; other studies also suggest benefit for other populations.

We're all affected by music. It has the power to inspire, uplift us, change our moods, and even alter consciousness.

My personal opinion is that the neutral position on the mood spectrum—what I called emotional sea level—is not happiness but rather contentment and the calm acceptance that is the goal of many kinds of spiritual practice.

When people are told to "eat many small meals," what they may actually hear is "eat all the time," making them likely to respond with some degree of compulsive overeating. It's no coincidence, I think, that obesity rates began rising rapidly in the 1980s more or less in tandem with this widespread endorsement of more frequent meals.

Imagine a world in which medicine was oriented toward healing rather than disease, where doctors believed in the natural healing capacity of human beings and emphasized prevention above treatment. In such a world, doctors and patients would be partners working toward the same ends.