the Stoics posited what they called the ‘directive faculty’ or hegemonikon, a kind of clearing house to which sensations are referred and in which behaviors are initiated. This is the most specific terminological equivalent in Stoicism for our word ‘mind.’
Graver defines the hegemonikon as the Stoics’ central integrating faculty — their nearest analogue to ‘mind’ — responsible for receiving sensation and initiating action, located in the chest and networked throughout the body via pneumatic extensions.
, Stoicism and Emotion, 2007thesis