Descartes, R. (1948). The passions of the soul, 1650. In W. Dennis (Ed.), Century psychology series. Readings in the history of psychology (pp. 25-31). East Norwalk, CT, US: Appleton-Century-Crofts.
http://dx.doi.org/10.1037/11304-004
In this piece Descartes presents one of the earliest attempts at a physiological psychology. This chapter is adapted from Descartes Selections, edited by Ralph M. Eaton, 1927, reprinted by permission of Charles Scribner's Sons. Following a foray into the parts and functions of the "bodily machine", the chapter branches out into the following areas: What is the Principle of All These Functions?; How the Animal Spirits are Produced in the Brain; How the Movements of the Muscles Take Place; How All the Members May Be Moved by the Objects of the Senses and by the Animal Spirits Without the Aid of the Soul; What the Functions of the Soul Are; That There is a Small Gland in the Brain in Which the Soul Exercises Its Functions More Particularly than in the Other Parts; How We Know that This Gland is the Main Seat of the Soul; Example of the Mode in Which the Impressions of the Objects Unite in the Gland Which is in the Middle of the Brain; Example of the Way in which the Passions Are Excited in the Soul; The Principal Effect of the Passions; How We Find in the Memory the Things Which We Desire to Remember; and How the Soul Can Imagine, Be Attentive, and Move the Body. (PsycINFO Database Record (c) 2016 APA, all rights reserved)