The focus of this article will not be on either the historical or political debate surrounding the concept of subsidiarity, which are important topics in themselves. Instead I will discuss the semantics of the concept of subsidiarity from the viewpoint of its socio-anthropological implications. The rationale for this purpose is the following. The evidences of contrasting—and even contradictory—meanings of the word subsidiarity remind us that, in order to understand this principle, we must, first of all, clarify the socio-anthropological foundations that support the different semantics of the term. This is a task to be accomplished as a premise for the justification of the way we use this principle in our theory and practice and why we resort to one semantic instead of another.