introspection (n.)

1670s, "action of closely inspecting or examining," noun of action from past participle stem of Latin introspicere "to look into, look at, examine, observe attentively," from intro- "inward" (see intro-) + specere "to look at" (from PIE root *spek- "to observe"). Meaning "action of searching one's feelings or thoughts" is from 1807.