Geulincx himself, besides two inaugural addresses at Leyden (as Lector in 1662, Professor Extraordinary in 1665), published the following treatises: _Quaestiones Quodlibeticae_ (in the second edition, 1665, entitled _Saturnalia_) with an important introductory discourse; _Logica Fundamentis Suis Restituta_, 1662; _Methodus Inveniendi Argumenta_ (new edition by Bontekoe, 1675); and the first part of his Ethics--_De Virtute et Primis ejus Proprietatibus, quae vulgo Virtutes Cardinales Vocantur, Tractatus Ethicus Primus_, 1665. This chief work was issued complete in all six parts with the title, _[Greek: Gnothi seauton] sive Ethica_, 1675, by Bontekoe, under the pseudonym Philaretus. The _Physics_, 1688, the _Metaphysics_, 1691, and the _Annotata Majora in Cartesii Principia Philosophiae_, 1691, were also posthumous publications, from the notes of his pupils. In view of the rarity of these volumes, and the importance of the philosopher, it is welcome news that J.P.N. Land has undertaken an edition of the collected works, in three volumes, of which the first two have already appeared.[1] The Hague, 1891-92.[2] [Footnote 1: On vol. i. cf. Eucken, _Philosophische Monatshefte_, vol. xxviii., 1892, p,200 _seq_.] [Footnote 2: On Geulincx see V. van der Haeghen, _Geulincx, Étude sur sa Vie, sa Philosophie, et ses Ouvrages_, Ghent, 1886, including a complete bibliography; and Land in vol. iv. of the _Archiv für Geschichte der Philosophie_, 1890. [English translation, _Mind_, vol. xvi. p. 223 _seq_.]]