Please answer a question about the following article about Heresy:

The term heresy is also used as an ideological pigeonhole for contemporary writers because, by definition, heresy depends on contrasts with an established orthodoxy. For example, the tongue-in-cheek contemporary usage of heresy, such as to categorize a "Wall Street heresy" a "Democratic heresy" or a "Republican heresy," are metaphors that invariably retain a subtext that links orthodoxies in geology or biology or any other field to religion. These expanded metaphoric senses allude to both the difference between the person's views and the mainstream and the boldness of such a person in propounding these views.

By definition, what contrast does heresy depend on?
an established orthodoxy