This article tackles the problem of institution building through rules from the point of view of social ontology and making reference to the concept of ‘constitutive rules’. In the first place, the author illustrates how institutions’ constitutive rules are subject to at least three types of limitations: ontological, structural and pragmatic. He then analyses a fourth kind of limitation that has not been discussed in the literature previously and which he defines as ‘mimetic’. More generally, he discusses the phenomenon of "institutional mimesis", whereby an institution can be constructed by "imitating" or representing a social or natural situation existing before the institution was established. In conclusion, he sets out to show the relevance that the concept of institutional mimesis can have for philosophy, sociology and history of law.
Keywords: Social ontology - Constitutive rules - Searle - Institutional reality - Legal concepts - Institutions