This article compares Canadian and Québec legislative practices over the last thirty years with an ethics of harmonious linguistic diversity. In the first section, the article describes the architecture of Canadian and Québec linguistic policies. In the second section, the examination turns to the elements of these policies which threaten the normative imperative of a harmonious linguistic diversity. Underscored in the analysis in this section is the strategist ideology grounded in power relations impelling the federal linguistic policy. So motivated, the federal policy ends up colliding with a counterpart ideology of identity (rather like that of Québec), an ideology which employs linguistic diversity and multiculturalism as its effective strategies. Today, such strategies are becoming more pronounced as cultural boldly assert themselves. The federal ideology of power is becoming less viable as spheres of identity reveal themselves to be defined as much by community as by state. On another scale and according to the variants, the same phenomenon manifests itself in Quebec's politics. In conclusion, this article postulates that, in order to establish a federal linguistic policy truly grounded in harmonious diversity, it is essential to substitute myths, regulating structures, and power-relation practices with notions characterized by heterogeneous solidarity. In Québec, the establishment of measures based on the mutual acknowledgement of diversity could also lead to a greater acceptance and adoption of French, the common language. Resume traduit du français par Pamela Lipson.