Not having heard something is not as good as having heard it; having heard it is not as good as having seen it; having seen it is not as good as knowing it; knowing it is not as good as putting it into practice.

XunZi (314 BCE-217 BCE), Xun Kuang also widely known as Xunzi "Master Xun", was a Chinese Confucian philosopher and writer who lived during the Warring States period and contributed to the Hundred Schools of Thought. A book known as the Xunzi is traditionally attributed to him.