Nature is defined in the dictionary as the totality of physical reality, or the total system of spatiotemporal phenomena and events, or as real and objective existence. It has also been defined as the world of mind and matter external to the observer, reality as observed. In the vernacular, nature is often described as the out-of-doors, as natural scenery or a landscape. Many people still take their image of nature from the nineteenth century British poet Alfred, Lord Tennyson, who described "nature red in tooth and claw." Or they see it as a benign, domesticated place to camp and play.

Ralph Waldo Emerson, a nineteenth century American thinker, wrote one of the most influential commentaries on nature. He suggested that "strictly speaking_all that is separate from us [humans] must be ranked under this name, Nature." Nature is multi-faceted, incorporating as it does, all the material world of...