places that do exist and that are formed in the very founding of society

Despite my sarcasm, these slightly obvious statements illustrate the technique Foucault is using as antithesis. In order to introduce the concept of heterotopia, Foucault sets up contrasts between the unreal and real; the main difference between utopias and heterotopias is that heterotopias coexist with Society in the domain of the real. So the reader, still yet to be formally introduced to the term “heterotopia,” knows one basic fact about it—it is real in the way heterotopias are not.

The use of antithesis also has symbolic meaning linguistically. Antithesis is one of the basic elements of dialectics, the use of argument and counter-argument. It demonstrates the yin and yang, the dual nature of reality. It represents it using the coding of language, but it’s a strong argument. As there is heaven and hell, God and Satan, Kanye West and 50 Cent, there are Utopias and Heterotopias.