 The most basic kind of polythetic approach holds that membership in a given class is not determined by the presence of a single crucial characteristic. Instead, the concept maps a cluster of characteristics and, to count as a member of that class, a particular case has to have a certain number of them, no particular one of which is required. To illustrate, imagine that there are five characteristics typical of religions (call this the “properties set”) and that, to be a religion, a form of life has to have a minimum of three of them (call this the “threshold number”). Because this illustration limits the number of characteristics in the properties set, I will call this first kind a “bounded” polythetic approach. For example, the five religion-making characteristics could be these: