Each of the Empedocles passages stresses "a double truth." This is a matter central to Eliot, but it is also closely involved in the work of Yeats, who, as l have suggested, has elucidated the procedure in his brief essay on "The Emotion of Multitude." This emotion, or sense of the universal in the particular, is born of "a double truth," somewhat in the mode of Quantum Mechanics where the chemical bond is the result not of a connection but of a "resonant interval" such as must obtain between the wheel and the axle. The means indicated by Yeats for achieving the emotion of multitude are familiar to modern students of Shakespeare under the head of "double plots," and these means were taught in antiquity, as essential to the aetiological epic or the Epyllion. (See Marjorie Crump's The 56+3 Epyllion from Theocritus to Ovid.)