There are in nature neither rewards nor punishments — there are consequences.

Robert Green Ingersoll (1833-1899) American lawyer, freethinker, orator

Essay (1881-08) “The Christian Religion,” “Is All of the Bible Inspired?” ch. 2, North American Review, Vol. 133, No. 297
    (Source)

Collected in Allen Thorndike Rice (ed.), The Christian Religion, ch. 1 (1882).

See Longfellow (1857).