Body and Soul in Ancient Philosophy

Galen and the Stoics: What each could learn from the
other about embodied psychology
Christopher Gill
Introduction
Galen and the Stoics are normally thought of as intellectual antagonists
or enemies. This is mainly because of Galen’s massive attack on Stoic
psychology in On the Doctrines of Hippocrates and Plato (PHP). 1 In
Books 1 –3, he criticises them, alongside Aristotle, for locating the ruling
part of the psyche 2 in the heart rather than the brain. One of the
major findings of Galen’s anatomical research, building on the work
of the Hellenistic doctors Herophilus and Erasistratus, was that the
brain functioned as the locus of sensation and motivation, and Galen directs
a barrage of arguments against the Stoics for retaining a heart-centred
view. Galen regards himself as providing an up-to-date, medically
informed, basis for the Platonic tripartite model in the Timaeus (69–72),
which also put the reasoning part of the psyche in the head, while locating
other psychological functions elsewhere in the body, emotions
such as anger in the breast and appetite in the stomach and liver. In
Books 4 –5 of PHP, Galen supplements the arguments about the location
of the ruling part of the psyche with a defence of the Platonic tripartite
account of psychological functions and an attack on the Stoic
unified theory, according to which emotions are seen as informed by
reason. So in both respects, the Stoics, especially Chrysippus, the
most systematic Stoic theorist, are presented here in a negative and antagonistic
light. 3
1 Galen’s works are referred to here by English titles and the standard Latin abbreviations.
2 I leave “psyche” untranslated since there is no adequate English equivalent, but
I treat it as a naturalised English word, and do not transliterate it.
3 On Galen’s programme in PHP, see De Lacy 2005, 48 – 50. On these two aspects
of Galen’s argument in PHP, and his engagement with Stoicism in this
connection, see two fundamental studies, Tieleman 1996 and 2003.