Line Themes in Human Design refer to the fundamental life orientations and characteristics associated with each of the 6 Profile Lines. These themes color every gate, channel, and expression in the BodyGraph: Line 1 — Investigator (security through knowledge; the need for a solid foundation before acting); Line 2 — Hermit (natural genius; the hermit who must be called out of isolation by others to share their gifts); Line 3 — Martyr (adaptability through trial and error; bonds made and broken; learning what works by discovering what doesn't); Line 4 — Opportunist (life operates through the network; the externalized Line 4 needs relationships and community to fulfill its purpose); Line 5 — Heretic (the practical revolutionary; universalizes solutions; carries the burden of others' projections — savior or scapegoat); Line 6 — Role Model (the sage; lives in three phases — the fall from the roof in the first 30 years, the "on the roof" period of observation from 30–50, and the descent as the model for others after the Kiron Return).