系

Formed as a compound ideograph:

丿 (삐침 별) — a slanted stroke representing a thread being drawn or caught;

糸 (가는 실 멱) — the radical for silk or thread, symbolizing connection.

The combined image suggests threads gathered and tied together, expressing the notion of binding or continuity.

In oracle bone script (甲骨文), the form depicts two skeins of silk held in the hand, visually representing tying or fastening. This evolved through bronze script into the modern simplified form.

Thus, 系 originally meant “to hang or tie by thread,” later extending to “to link” or “to belong.”

체계 (體系) — a structured system or organization

계통 (系統) — lineage; classification; order

유계 (有系) — connected or affiliated

무계 (無系) — disconnected, unaffiliated

The term often appears in scientific and philosophical vocabulary:

생태계 (生態系) — ecosystem

태양계 (太陽系) — solar system

언어계 (言語系) — linguistic system

In contrast with 界 (boundary), which divides categories, 系 unifies — representing a network of continuity or belonging.

In Confucian and Daoist thought, the idea of tying without binding (繫而不縛) embodies harmony — the gentle cohesion that connects individuals, families, and society without constraint.

系, therefore, symbolizes continuity and belonging, the invisible threads linking heaven and earth (天人之系), or teacher and disciple (師徒之系).

In the sciences, this ancient metaphor continues as the modern “system” — the structured web of interrelations that sustains coherence in complexity.