Eternal Recurrence and The Cay Science 229For Nietzsche, it was a problem solved, and his delight soared into
ecstatic rapture. He shed "tears of joy," as he wrote to Peter Gast on
August 14,1881 (£6,112).
Eternal recurrence is supposed to be the cold mechanical and math-
ematical law of the universe, but for this very reason it leaves us cold.
How can it find its way into experience? It may well have happened to
Nietzsche in roughly the following way: an idea that was already familiar
to him as a religious fantasy and intellectual intuition now carried the
authority of exacting science. In early 1881, he read Julius Robert
Mayer's Beiträge ^r Dynamik des Himmels (Celestial Dynamics, 1848) and
sent an enthusiastic letter to Peter Gast, who had brought this work to
Nietzsche's attention: "In splendid straightforward and joyous books
like this book by Mayer, you can hear the harmony of the spheres: a
music that is accessible only to a man of science" (B 6,84; April 16,
1881).
Julius Robert Mayer, a doctor who died in 1878, was also a distin-
guished natural scientist whose research focused on materialism. He
refined the principle of the conservation of material substance by
employing the hypothesis of the conservation of energy. The elemental
force in the universe, he taught, could be altered only in quality; the quan-
tity would remain constant Change was nothing but a transfer of energy:
energy into matter, heat into motion, and so forth. Between these con-
versions, constant proportions in the sum total could be calculated.
Nietzsche later dissociated himself from Mayer, accusing him of
introducing an ominous element of divine omnipotence into the mate-
rial harmony of the spheres. For the time being, however, he was enthu-
siastic, and we can assume that reading Mayer contributed to his vision
at the Surlej boulder. Mayer had not linked his law of the conservation
of energy to a doctrine of returning constellations and conditions. That
was Nietzsche's contribution, deduced from his conjecture of a perpet-
ual continuum of time, which was amply documented in the scientific
and materialist literature that he studied during the course of these
months, despite excruciating pain in his eyes and head.