Direct observation of the luminous essence of nature is for me indispensable. Robert Delaunay
Direct observation of the testimony of the earth ... is a matter of the laboratory, of the field naturalist, of indefatigable digging among the ancient archives of the earth's history. Henry Fairfield Osborn
In dealing with the China problem, the British and American side, which had particularly strong interests in China, should have based its judgments about the origins of the problem on direct observation of the actual circumstances at the time. Hideki Tōjō
Our conviction that green cheese makes up a negligible fraction of the Moon's interior comes not from direct observation but from the gross incompatibility of that idea with other things we think we know. Sean M. Carroll