AbstractTHE VATICAN MANUSCRIPT OF SPINOZA’S ETHICA S u m m a r y The article focuses on Spinoza’s manuscript found in The Vatican Apostolic Library and published by L. Spruit and P. Totaro in the book The Vatican Manuscript of Spinoza’s Ethica (2011). The identification of the text became possible as the result of their arduous research in which the name of a Danish scientist N. Stensen, the author of several letters usually published in the collections of Spinoza’s letters, played a crucial part. The manuscript Vat. Lat. 12 838 is the only known editorial copy of Spinoza’s manuscripts and its origins are dated as early as 1675, i.e. before the publication of Opera posthuma. The comparison of its contents with the Ethics, published in 1677, points to many differences, most of which are typical mistakes, occurring probably either in Spinoza’s manuscript, or in the editorial copy, or else made by the typesetter and not expunged during the editorial proofreading. However, the editors emphasize the importance of some substantive differences of the text for the interpretation of Spinoza’s Ethics. The history of the manuscript and the circumstance it found its way to the library of The Holy Office and thence to the Vatican Apostolic Library enabled the editors to put forward some hypotheses concerning the circulation of Spinoza’s manuscripts in the period when the censure was issued against him after the publication of the Tractatus Theologico-Politicus.