The explanation of the institutions has always fallen into a paradox. From an individualistic perspective, consistent with the assumptions of the theory of action, it is difficult to understand how the aggregation of several actions, without normative and social premises for the action itself, can produce complex institutions. In a normative perspective, consistent with the assumptions of the neo-institutionalism approach, which would seem hypothetically more adequate, once we understand what an institution is, it becomes hard to explain its changes and its transformations over time. In this article we are interested in showing the salience of a systemic-evolutionary approach to explain the emergence of the modern political institutions, that means also the onset of modern politics. As an evolutionary phenomenon, the rise of modern politics is a part of the more general evolutionary process that leads to the affirmation of modern society, that is a type of society characterized by a particular form of functional differentiation, at the origin of the structural separation between the properly “political” power and the economic, social and symbolic-cultural ones. It is this structural differentiation for functions that leads to the birth of modern political power and its own institutions. A systemic-evolutionary approach allows to overcome the above mentioned paradox, since it is able to hold together both the normative dimension needed for the functioning of the institutions and the dimension of the change needed to understand how institutions are transformed over time. And this perspective can also be useful to understand other very important dynamics, such as the recombination of elements and institutional forms of the past to give life to new institutions at all, and also the identification of some critical junctures, which allow the course of history to take a certain direction when different outcomes were still possible.