the theologian Caterus of Antwerp, while the Second and Sixth, collected by
Mersenne, are from various theologians and mathematicians. In the second
edition there were added, further, the Seventh Objections, by the Jesuit
Bourdin, and the Replies of the author thereto. The four books of the
_Principia Philosophiae_, published in 1644 and dedicated to Elizabeth,
Countess Palatine, give a systematic presentation of the new philosophy.
The _Discourse on Method_ appeared, 1644, in a Latin translation, the
_Meditations_ and the _Principles_ in French, in 1647. The _Treatise on the
Passions_ was published in 1650; the _Letters_, 1657-67, in French, 1668,
in Latin. The _Opera Postuma_, 1701, beside the _Compendium of Music_
(written in 1618) and other portions of his posthumous writings, contain
the "Rules for the Direction of the Mind," supposed to have been written in
1629, and the "Search for Truth by the Light of Nature." The complete works
have been often published, both in Latin and in French. The eleven volume
edition of Cousin appeared in 1824-26.[1]

[Footnote 1: Of the many treatises on the philosophy of Descartes those of
C. Schaarschmidt (_Descartes und Spinoza_, 1850) and J.H. Löwe, 1855, may
be mentioned. Further, M. Heinze has discussed _Die Sittenlehre des
Descartes_, 1872; Ed. Grimm, _Descartes' Lehre von den angeborenen
Ideen_, 1873; G. Glogau, _Darlegung und Kritik des Grundgedankens der
Cartesianisch. Metaphysik (Zeitschrift für Philosophie_, vol. lxxiii. p.
209 _seq_.), 1878; Paul Natorp, _Descartes' Erkenntnisstheorie_, 1882;
and Kas. Twardowski, _Idee und Perception_ in Descartes, 1892. In French,
Francisque Bouillier (_Histoire de la Philosophie Cartésienne_, 1854) and
E. Saisset (_Précurseurs et Disciples de Descartes_, 1862) have written
on Cartesianism. [The _Method, Meditations, and Selections from the
Principles_ have been translated into English by John Veitch, 5th ed.,
1879, and others since; and H.A.P. Torrey has published _The Philosophy
of Descartes in Extracts from his Writings_, 1892 (Sneath's Modern