Add to ORKGWith the aim of highlighting some conceptual elements found in Spinoza's letters, the article will focus on the texts – written by Spinoza or addressed to Spinoza – through which it is possible to reconstruct the subject of freedom of thought and speech. This theme emerges with great clarity in the correspondence with Heinrich Oldenburg, then Secretary of the Royal Society. In fact, it is in the name of this freedom that Spinoza rejected the prestigious chair offered by the University of Heidelberg. Moreover, the philosopher interrupted the drafting of the Ethics in order to publish the Theological-Political Treatise, so that he could get to the heart of the debate over the powers and limits of the imperium democraticum in the Dutch Golden ...