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.

As a species, we are most animated when our days and nights on Earth are touched by the natural world. We can find immeasurable joy in the birth of a child, a great work of art, or falling in love.

In nature, a child finds freedom, fantasy, and privacy: a place distant from the adult world, a separate peace.

The woods were my Ritalin. Nature calmed me, focused me, and yet excited my senses.

Today's children are living a childhood of firsts. They are the first daycare generation; the first truly multicultural generation; the first generation to grow up in the electronic bubble, the environment defined by computers and new forms of television; the first post-sexual revolution generation; the first generation for which nature is more abstraction than reality; the first generation to grow up in new kinds of dispersed, deconcentrated cities, not quite urban, rural, or suburban.

As the nature deficit grows, another emerging body of scientific evidence indicates that direct exposure to nature is essential for physical and emotional health. For example, new studies suggest that exposure to nature may reduce the symptoms of Attention Deficit Hyperactivity Disorder (ADHD), and that it can improve all children's cognitive abilities and resistance to negative stresses and depression.

One of my students told me that every time she learns the name of a plant, she feels as if she is meeting someone new. Giving a name to something is a way of knowing it.