[The pineal gland as physical tool of the soul faculties: a persistent historical connection]

The anatomic seat of the human soul has been a controversial matter of discussion in the philosophical, theological and scientific fields throughout history. One of more known hypotheses on this subject was proposed by Descartes, for whom the soul would host in the pineal gland, a brain body with a special location that would adequately address the functionalism of the human body.

In this work, we discuss the historical influences which made possible the Cartesian model of the relationship between spirit (res cogitans) and body-machine (res extensa) and the technical bases of his dualism doctrine. In philosophical terms, Descartes supported Augustine approaches and in physiological and anatomical terms adopted some theories of the classical Antiquity, essentially the proposals of Alexandrian pneumatic school (Herophilos, Erasistratus) in relation to the animal spirits. Descartes might also have known the hypotheses of some contemporary anatomists (Diemerbroeck) which established the location of sensorium commune in the pineal gland.

Although Cartesian theories had strong criticism even in his time, some aspects of these postulates remained up to mid 19th century.