第56页 The Structure of Urban Arifacts

To say that the medieval city is organic reveals an absolute ignorance of the political, religious, and economic structures of the medieval city, not to mention its spatial structure.

Here, Rossi attacks the very "formal" reading of urban forms. For Rossi, form, as the category that the urban study is based on, is merely a manifestation of political, religious, and economic forces. While form is autonomous from function, it's conditioned by these forces. This reminded me of the saying that "architecture is not a knowledge of form, but a form of knowledge."