Why it matters

Bekker's De Betoverde Weereld (1691) applied Cartesian metaphysics to the question of spirits, attacking belief in sorcery and diabolical possession and questioning the devil's very existence; the scandal it caused led to his deposition from the Dutch Reformed ministry, and it is regarded as one of the most controversial books of the early Enlightenment. This 1694 Amsterdam set is the first French edition, the vehicle by which the argument reached the wider francophone republic of letters.

Why we're looking

A complete-looking four-volume set in uniform contemporary marbled calf with the six plates, at €1,000 (~$1,139), sits below the US$1,400 asked for a Good but complete set at Sam Gatteno Books and well under the US$2,500 signed Very Good set at Moroccobound Fine Books — though the margin largely reflects the missing portrait, and French auction reality is softer, with a comparable set realizing €319 at Artcurial.

Watch out for

The seller states the engraved author portrait is lacking, and dealer descriptions of complete sets confirm a full copy carries that frontispiece portrait in vol. I alongside the six plates in vol. IV — so this set is short of a wanted element, which matters for resale. "Good condition" is doing a lot of work here with no detail on joints, headcaps, or text completeness, and no pagination/collation is given, so ask for a leaf-by-leaf check against the standard collation. Dealer descriptions of other copies also note Bekker's autograph signature at the end of the épître in each volume as a feature of the French edition; the listing is silent on whether this copy has them, which is worth asking.