Why it matters

Jean Prestet moved in Nicolas Malebranche's philosophical circle and was among the first to write mathematics in French rather than Latin, helping bring algebra to a wider audience — Abraham de Moivre reportedly taught himself the subject from an earlier edition of this same work. But this particular edition carries a more specific, citable distinction: scholars writing in the peer-reviewed journal Historia Mathematica have identified pages 140–150 of Volume I as containing Prestet's early precursor work toward the Fundamental Theorem of Arithmetic — the principle that every integer has a unique prime factorization, not rigorously proven until Gauss in 1801. The scholarship is careful here: Prestet never states the theorem outright, and it's genuinely debated whether he grasped its full implications. But the fact that mathematicians are still parsing his 336-year-old corollaries to answer that question is itself a real mark of the book's significance.

Why we're looking

This is actually two separate listings, not one — Tome I and Tome II, sold individually by the same seller, with nothing in either description indicating a match. Side-by-side comparison confirmed it: matching binding, matching pagination continuity, matching publisher and year. Together they form a complete original set. That completeness carries real, verified value. A matching 2-volume set of this exact edition — same publisher, same year, matching pagination — is currently offered by a Paris specialist dealer at €1,200 (~$1,390). Our two volumes, bought as the seller had them listed, total roughly $515 combined. That's the set at about 37% of the verified market price for an assembled pair — a gap driven by the seller offering two orphaned halves rather than the complete work they'd become once reunited.

Watch out for

Both volumes show the wear expected of a 336-year-old working copy — lightly yellowed pages and typical age wear to the bindings, with no major tears or losses affecting text. Neither copy is pristine, and neither claims to be. Given that condition sits well below the assembled comp's own described condition (rubbed binding, worn caps and corners, light staining), the price gap here reflects genuine assembly value, not a like-for-like match in condition — worth stating plainly rather than implying these two volumes are equivalent to that specific comp copy.

Note: Buy both listings together: Tome I at https://www.ebay.fr/itm/237042269083 ($174) and Tome II at https://www.ebay.fr/itm/336772444210 ($353).