Nature is the environment for the development and continuation of human life. At the same time, productive labor, as a medium in the process of material exchange between man and nature, is the starting point for the formation and development of human social relations. In the process of processing natural materials, people form the relationship between people-- relations of production, and thus form national, class, family and other complex social relations.
The argument is supported by the statement that man is a part of nature, because man is also an animal.