PREFACE
THE aim of this edition is to present to English readers all the philosophical works of Descartes which were originally intended for publication. More than one valuable translation of the treatises which give a general view of Descartes' system has already appeared. But certain others which are quite indispensable for a thorough comprehension of his views have not yet been made accessible to English readers. The chief of these are probably the "Rules for the Direction of the Understanding" and the "Passions of the Soul." As a matter of fact the "Passions of the Soul" was actually translated into English by an anonymous writer in the year 1650, but this translation is now exceedingly rare, and no other has appeared until the present time. In the "Passions" we find the full exposition of Descartes' theory that mental and physiological phenomena may be explained by simple mechanical processes. It was a completely new departure to state that such matters were capable of being interpreted thus, and one that has had a fundamental influence on the psychology and physiology of the present time.
It is also most important to mark the result of Descartes' speculations on contemporary thought; and the complete translation now presented of the "Objections" directed against the "Meditations," published together with Descartes' replies thereto, in the second volume, will enable the English reader
