Sweden has had laws protecting nature for about a hundred years. In this paper the views of nature and the values that serve as a rationale for protective measures are analyzed as results of a social process characterized by the dialectic relationship between institutions and discourse. Critical discourse analysis (CDA) is used to study this relationship and the discursive practices used by institutions, which reproduce or reshape views of nature that define the relationship between society and nature. Institutional design contributes to shaping discourse in the field of nature protection, while being originally shaped by discourse. In Sweden, the national park is an institution that reproduces a view of nature as the wild and untamed opposite of society, and the natural reserves reproduce a view of nature as holder of a multi-faceted set of values intertwined with society. However, the most recently formed national park, the marine national park of the Koster sea includes resource values that threaten the hegemony of arcadian discourse within the institution and indicates social change.