反

Formed as a compound character:

厂 (“cliff, slope”) depicts a rocky wall.

又 (“hand”) depicts a hand reaching or grasping.

Together, the original sense was “to grasp the cliff with the hand and climb”.

Later, this meaning shifted: with the hand-radical 扌 added, 扳 (“to pull, drag”) preserved the climbing sense, while 反 developed into “to turn back, to reverse, to oppose.”

Semantic range:

- to turn back, return (돌아오다, 돌이키다);

- to reverse, invert (뒤집다, 거꾸로 하다);

- to oppose, resist (반대하다);

- by extension: to betray, rebel, revolt (배신하다, 반역하다).

반대 (反對) — opposition, to oppose

반사 (反射) — reflection (of light, sound)

반역 (反逆) — treason, rebellion

반성 (反省) — self-reflection

반동 (反動) — reaction, counteraction

Distinctions 反 vs. 返:

反 - to turn back in a general or abstract sense (reversal, opposition, reflection).

返 - to return something to someone specifically (to give back, repay).

In Confucian and Daoist texts, 反 often carries the meaning of “returning to the origin” (反本, “return to the root”). Laozi’s Dao De Jing emphasizes 反者道之動 (“returning is the movement of the Dao”), pointing to reversal and return as fundamental patterns of the cosmos. Thus, 反 is not only opposition but also renewal and cyclical return.