a sober account of nature as not necessarily the work of intelligent purpose, but as an ordered realm of beings belonging to classes with definite characteristics and, in the case of living beings, functions and specific ways of thriving that reveal not only what is, but what is good. To understand what a heart is means to comprehend what a healthy heart is and does. To know what a beaver is means to grasp its thriving existence as a being that builds dams and eats bark and raises young, for which it is good to do these things and good to have the clean water and trees and freedom that they require. Something analogous, though much more complex, is true for human beings.
This paragraph addresses the above questions about nature (albeit too briefly to be exhaustive).