This paper aspires to show the often-obscured structure of alternatives in education. Alternative education is generally understood as an umbrella term for educational thought and practice for and in schools differing from an assumed 'mainstream', where 'alternative' is often taken to mean 'better'. In many cases, 'mainstream' serves as an empty signifier that can be substituted by various forms of criticism. Just as progressive education is supposed to remedy all the ills of traditional education, alternative education is often positioned as a safe place to retreat to, away from the mainstream. I argue that this leads to a dichotomous structure. The mainstream, however, is not an empirical reality, for example, a specific form of curriculum, differentiation of different types of schooling, or anything else. 'Mainstream' serves as a generic critical reference point. My argument is developed through a series of historical discussions around alternative education explored through the lens of contemporary analysis of the category. I then offer a more systematic account of the terminology in order to establish a perspective from which to assess the flaws and problems of alternative education alongside its potential virtues and benefits.