Now, my tree-climbing days long behind me, I often think about the lasting value of those early, deliciously idle days. I have come to appreciate the long view afforded by those treetops. The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

This tree house became our galleon, our spaceship, our Fort Apache...Ours was a learning tree. Through it we learned to trust ourselves and our abilities.

We do not raise our children alone.... Our children are also raised by every peer, institution, and family with which they come in contact. Yet parents today expect to be blamed for whatever results occur with their children, and they expect to do their parenting alone.

The dugout in the weeds or leaves beneath a backyard willow, the rivulet of a seasonal creek, even the ditch between the front yard and the road-all of these places are entire universes to a young child.

The Centers for Disease Control (CDC) reports that the number of overweight adult Americans increased over 60 percent between 1991 and 2000. According to CDC data, the U.S. population of overweight children between ages two and five increased by almost 36 percent from 1989 to 1999.

Natural play strengthens children's self-confidence and arouses their senses-their awareness of the world and all that moves in it, seen and unseen.

Nature-deficit disorder describes the human costs of alienation from nature, among them: diminished use of the senses, attention difficulties, and higher rates of physical and emotional illnesses. The disorder can be detected in individuals, families, and communities.