"kernels of extension" just floated up for me. love it. in math, a kernel of a function is the inverse image in the domain of the identity element in the range. eg, Duncan Bell's "sum of contexts" approach to a concept of 'liberalism' is a kind of kernel. Dahl's behavioral formalization is also one.
democracy: almost always used as both symbol, more or less opaque, and analytic concept, more or less formal & deliberate. deliberate concepts range from from ideal types to kernels of extension to categorization like 'illiberal' - all strictly nominal tools geared to a particular analysis.
