Λογιστικόν (logistikon)
Rational / calculating part — head
Logistikon — the rational, calculating part of the soul; the seat of deliberation and of the recognition of the Good. In Republic IV (441e) Plato concludes that 'it is fitting for the calculating part to rule, since it is wise and exercises forethought on behalf of the entire soul.' The contrast is internal: it is the part that says 'do not drink' to a thirsty body — the part that knows what is best across time, against the appetitive pull of the present moment. Timaeus 69e localises the immortal logistikon in the head — 'in order that this part might exercise its rule from the highest place, and that the rest of the body might be its subject and inhabit beneath it.' The neck is given precisely as the isthmus separating the immortal head from the mortal lower parts. We anchor the rendered point at the third-eye / glabellar height as a visible proxy for Plato's spherical-skull seat of nous, following the Timaeus's own description of the head as the divine pilot of the body.
Point 1 of 3 in Plato's Tripartite Soul (Republic IV)
Cross-tradition overlaps
No overlapping points are registered for this point.
Sources
Plato, Republic IV.441e (primary_canonical)
“It is fitting that the calculating part should rule, since it is wise and exercises forethought on behalf of the entire soul.”
Plato, Timaeus 69e–70a (primary_canonical)
“The gods, imitating the spherical shape of the universe, enclosed the two divine revolutions in a spherical body, that which we now call the head, the divinest part and ruler of all that is in us.”