At one end of the continuum, people who are strongly anthropocentric care only about the welfare of humanity; all other species are resources to be exploited. They would be content in a world dominated by domestic species as long as there was sufficient food, water, and oxygen and whatever other elements of nature are necessary to provide people with healthy, happy lives. Conversely, people who are strongly biocentric consider Homo sapiens no more intrinsically important than any other species. Because of the overwhelming threats people pose to other species, biocentrists would prefer a world with a far lower human population living lifestyles that greatly reduced humanity's impact on wild species, even if it compromised their material well-being.
By describing these furthermost ends of the continuum, it becomes apparent that Soule leans toward the biocentric pole whereas Kareiva and Marvier are closer to the anthropocentric pole, but that they are much closer to one another than to either of the poles.There is no such continuum. Nobody is even slightly biocentric. Some people are particularly fond of wildlife, just as others are of food, music, sports or cars. Some people may be so fond of cars or wildlife and so disrespectful of fellow humans that they may be willing to rob other people in order to get more joy from cars or wildlife. But that is all. There is no such thing as the intrinsic value of species. There are only the values each of us attaches to the things that surround us. We can estimate those values by observing human acts. And when people's words are incompatible with their other acts we can safely disregard the words.