The article aims at defining the nature of logical models and the syntax in which they are built. Many problems in the social universe are not manageable experimentally or statistically, owing to the incapacity to materially alter the course of events or to the lack of sufficiently large data distributions. When investigating current or past events,, historians and sociologists are confronted with areas of inquiry characterized by one or few cases and many dichotomous variables. In order to deal with such areas in an explicit and intersubjectively accountable way, this work proposes some models for the control of empirical causal hypotheses which are based, at their simplest level, on bivalent truth functional syntax and on the logic of single and compound necessary and sufficient conditions, representing an operational development of traditional Millian inferential methods.