Another celebrated essay is “A Discussion of Heaven,” in which he attacks superstitious and supernatural beliefs. One of the work’s main themes is that unusual natural phenomena (eclipses, etc.) are no less natural for their irregularity—hence are not evil omens—and therefore men should not be concerned at their occurrence. Xunzi’s denial of supernaturalism led him into a sophisticated interpretation of popular religious observances and superstitions. He asserted that these were merely poetic fictions, useful for the common people because they provided an orderly outlet for human emotions, but not to be taken as true by educated men. There Xunzi inaugurated a rationalistic trend in Confucianism that has been congenial to scientific thinking.
Heaven never intercedes directly in human affairs, but human affairs are certain to succeed or fail according to a timeless pattern that Heaven determined before human beings existed...
Thus rituals are not merely received practices or convenient social institutions; they are practicable forms in which the sages aimed to encapsulate the fundamental patterns of the universe. No human being, not even a sage, can know Heaven, but we can know Heaven’s Way, which is the surest path to a flourishing and blessed life. Because human beings have limited knowledge and abilities, it is difficult for us to attain this deep understanding, and therefore the sages handed down the rituals to help us follow in their footsteps.
Relevant quotes:
Original text is from Discourse on Heaven of Xunzi:
The Britannica says:
Stanford Encyclopedia