The Mistake of the Machine — G.K. Chesterton

"What sentimentalists men of science are " exclaimed Father Brown, "and how much more sentimental must American men of science be Who but a Yankee would think of proving anything from heart-throbs? Why, they must be as sentimental as a man who thinks a woman is in love with him if she blushes. That's a test from the circulation of the blood, discovered by the immortal Harvey; and a jolly rotten test, too." "But surely," insisted Flambeau, "it might point pretty straight at something or other."