 A first step in the direction of such an understanding of styles is the explicit analysis of the notion of similarity. The standard way of cashing out what it means for an object to be similar to another object is to require that they co-instantiate properties. In fact, this is the idea that Quine (1969: 117–118) and Goodman (1972: 443) had in mind in their influential critiques of similarity. The two most prominent formal frameworks that develop this idea are the geometric and contrast accounts (see Decock and Douven 2011 for a discussion).