Understanding (Verstehen, act of), 6-7, 12-13, 85-86, 100fn, 133, 147fn, 142-154, 156, 158, 160-165, 167-170, 173-174, 180-184, 183fn (as hearing), 200-201, 220-223, 262-263, 269-270, 279-280, 289-293, 295-297, 305-315, 316fn, 324-326, 334-340, 359-361, 427, et passim; fundamental existential, 143- 144, 148, 336; its most primordial knowing is circle, 152, 314-315. See also Project; Sight (BT)