Dutch media are reporting that Leen Spruit has discovered a manuscript of Spinoza's Ethics in Vatican library. (By chance on Monday in Oxford, I had heard about this from Pina Totaro (CNR, Roma), who is involved in publication of the manuscript.) This is exciting news! The Dutch article writes that this ms was submitted to the Inquisition by Spinoza's ex-friend Nils Steno in 1677. The team that is analyzing the ms suspects Steno obtained the manuscript from Spinoza's interlocuter, Ehrenfried Walther Tschirnhaus.
The newspaper article subtly implies, however, that this ms is more authentic than the one published in Spinoza's Opera Posthuma. The article suggests that this ms proves that the posthumous work must have been edited and changed from the manuscript Spinoza left for his editors (now lost, presumably destroyed). But it is not impossible that Spinoza made some changes to the Ethics after he circulated the version now found in the Vatican library. Moreover, the Dutch translation that accompanied the Ethics in the Opera Posthuma contains subtle differences -- often clarifications --, suggesting that the editors were cautious in altering the Latin. Anyway, until the world's expert on these matters, Prof. Piet Steenbakkers, weighs in, I remain skeptical about the suggestion that we will need to study this manuscript as the authentic Spinoza.
Update: the manuscript will be invaluable to help figure out the extent of Spinoza's intellectual development during the last few years of his life. In particular, it may allow us to discern the impact, if any, of Spinoza's non-trivial correspondence with Tschirnhaus (and their intermediary, Schaller). Moreover, the Dutch newspaper reports also provide more evidence for the idea that the Ethics may have originally been conceived in four parts (or that material that was intended for a fourth part, ended up in the final part, which has a rather sharp break between proposition 20 en 21).