B.d.S. Opera Posthuma. [Amsterdam: Jan Rieuwertsz], 1677. Latin and some Hebrew. First edition. With several in-text woodcut illustrations.
This edition of Baruch Spinoza's works was published shortly after the philosopher's death. It represented the earliest printing of writings never published in his lifetime, including books that would become his most important, influential, and best-known works. The edition was submitted for publication by a small circle of Spinoza's friends; the printer's name was not indicated, and the simple initials "B.d.S." appeared in place of the author's name.
Printed for the first time in the present book are Spinoza's major compositions, most prominently the work titled "Ethica" ("Ethics"), widely regarded as one of the most important books on philosophy of all time. In addition, appearing for the first time in this compendium are the works "Tractatus Theologico-Politicus" ("Theologico-Political Treatise"); "Tractatus de Intellectus Emendatione" ("Treatise on the Emendation of the Intellect" or "On the Improvement of the Understanding"); "Epistolae" – the letters of Baruch Spinoza; and an additional work (never fully completed, but published in Hebrew under the title "Dikduk Sfat Ever") on the grammatical rules of the Hebrew language, prepared by Spinoza in response to a request from his friends.

Baruch (Benedictus) Spinoza (1632-1677), Dutch-Jewish philosopher; referred to by Georg Wilhelm Friedrich Hegel as "the pinnacle of modern philosophy." His radical thinking aroused strident opposition and hostility in its day, and eventually led to his banishment and excommunication at the hands of both the Christian and Jewish communities. Spinoza actually published very little of his own literature during his lifetime, in part out of fear he would be declared a heretic, and what he did publish was mostly done so anonymously. His professional career was mostly devoted to making a living as a lens grinder, and other than maintaining a small, tight circle of friends and conducting a limited correspondence through letters, he lived his life almost entirely as a hermit. His major works appeared in print only posthumously, in the volume presented here.

[40], 614, [34], 112, [8] pp., approx. 20.5 cm. Without the frontispiece portrait (absent in most copies). Good condition. Stains. Handwritten notations and marks (old) on several leaves. Minor tears and worming (with negligible damage to text) to edges of several leaves. Mended tears to edges of title page. New parchment binding with gilt title on spine.

See: Abraham J. Karp, From the Ends of the Earth: Judaic Treasures of the Library of Congress (Washington, DC: Library of Congress, 1991), pp. 6-8.