The article explores the possibility, conditions and limits of freedom in the Spinoza’s system of absolute necessity. In the absence of the term emancipatio, it is taken as object of investigation the pair of terms servitus-libertas: these are two key terms in the first, fourth and fifth part of Ethics. Two forms of servitus are distinct and described: the first consists in the ontological dependence, and insuperable necessity of any mode, including humans, compared to the substance. In this sense, God is the only cause of the essence, existence and action of the mode. The second form of servitus, relative, is established between the modes, to the extent that the man is a part of the Nature, whose power infinitely surpasses that of any single mode. However, when a mode fails to act, by divine determination, predominantly expressing its own nature, such action is said free, as it is not determined predominantly by external causes. The two conditions that make human freedom possible are the true knowledge and a well-constructed State, which guarantees primarily the securitas of citizens. The main aim of the article is to show that Spinoza’s freedom postulates the necessity, because the freedom, understood as contingent choice or indifferent arbitrariness, is a pure fiction. The philosophy of Spinoza is not intended to demonstrate how the freedom is possible despite the necessity; but, on the contrary, that true freedom is possible only in a system of necessity. In this sense, freeing from inveterate prejudices, Spinozian philosophy can be considered emancipatory in the highest degree.