Long neglected, even mistreated, the Short Treaty has acquired, since the work of Filippo Mignini, the status of the first formulation of Spinoza's system. But for this very reason, it still too often remains in the shadow of Ethics. The Short Treatise deserves to be read (and reread) for itself, and not only with a view to understanding the genesis of Ethics. This is the main goal pursued by the contributions of this volume: to show the singularity of the text, its usefulness for addressing contemporary questions, and for shedding new light on Ethics and political treatises.