Two works bound in one volume: first edition of Principia philosophiae followed by the first Latin edition of Specimina philosophiae. Complete with blank leaves b4 and 2Q4.
Printer's mark representing Minerva and her owl, as well as the motto “Ne extra oleas” on the title page. Numerous in-text engravings.
Bound in full calf, spine with five raised bands framed in gilt, elaborately decorated in gilt, gilt arms of the Society of Writers to the Signet at center of boards framed in blind, marbled endpapers, speckled edges. Library shelfmark glued to the pastedown endpaper, additional penned shelfmarks on the pastedown, and a manuscript ex-libris of the Signet Library, “Ex Lib: | Bibl: Scribar | Sig: Reg:” on the title page. Joints, spine-ends and corners restored, more foxing on the first six leaves, on the title page of the Specimina and the last four leaves of the volume. Some spots to the boards. Unusual paper defect around the author's name on the title page of Principia, present in other copies (Library of Congress, BnF), small wormhole to the lower margin of this same page, burrowing to p. 129 of the “Specimina”. A few faded letters on 4 lines where two pages were joined together (pages 296–297).
First Latin edition of the Discourse on the Method containing the first occurrence of the famous “cogito ergo sum”.