Monks, when the uninstructed worldling experiences a painful feeling, he sorrows, grieves, and laments; he weeps beating his breast and becomes distraught. He feels two feelings - a bodily one and a mental one. Suppose they were to strike a man with a dart, and then strike him immediately afterward with a second dart, so that the man would feel a feeling caused by two darts. So too, when the uninstructed worldling experiences a painful feeling, he feels two feelings - a bodily one and a mental one.
-- The Buddha, SN36:6