One of the main goals of this book is to determine if, in the works of some of the key authors in the history of Italian political philosophy, a notion of “efficacy” can be found. In legal philosophy, “efficacy” is the capacity a norm has to effectively influence citizens’ behavior. The “principle of efficacy” is that according to which an order or rule exists as such when it is followed effectively in practice. Here by “efficacy” I mean the idea that normative phenomena are self-justifying, without reference to extrinsic systems of value (such as “natural law”)....

One of the main goals of this book is to determine if, in the works of some of the key authors in the history of Italian political philosophy, a notion of “efficacy” can be found. In legal philosophy, “efficacy” is the capacity a norm has to effectively influence citizens’ behavior. The “principle of efficacy” is that according to which an order or rule exists as such when it is followed effectively in practice. Here by “efficacy” I mean the idea that normative phenomena are self-justifying, without reference to extrinsic systems of value (such as “natural law”)....