This short essay argues that instead of having a given hierarchy among disciplines of human knowledge, there is a changing and multifarious construction of such disciplines. This may be seen in the way in which disciplines such as economy, sociology, political science and law have built specific understandings of reality as a whole, to the point that it is possible to refer to economic, social, political or legal manners of construction of reality. This leads to the notion of horizontal interdisciplinarity, given the fact that disciplines of human understanding are all capable of building knowledge and of forging new and different epistemic frontiers.