True wisdom cannot enter a mind crowded with preconceived opinions; to receive new understanding, we must first learn to unlearn and empty our cups.
“Scholar Tokusan – who was full of knowledge and opinions about dharma — came to Master Ryutan and asked about Zen.
At one point, Master Ryutan re-filled his guest’s tea cup but did not stop pouring when the cup was full. Tea spilled out and ran over the table. “Stop! The cup is full!” said Tokusan.
“Exactly,” said Master Ryutan. “You are like this cup; you are full of ideas. You come and ask for teaching, but your cup is full; I can’t put anything in. Before I can teach you, you’ll have to empty your cup.”
This is harder than you might realise. By the time we reach adulthood we are so full of information that we don’t even notice it’s there. We might consider ourselves to be open-minded, but in fact, everything we learn is filtered through many assumptions and then classified to fit into the knowledge we already possess.”
Source: https://www.thoughtco.com/
Image: A postage stamp issued by China in 1997 shows the Buddha from the Maijishan grottoes located along the ancient Silk Road near Tianshui City, Gansu province. The grottoes were dug on a precarious cliff of the Xiaolong Mountain in the forest 1600 years ago, and got their name because the mountain is shaped like a “piled wheat straw of a rural family.” Now, 194 caves are preserved, containing more than 7,200 small mud figures, stone sculptures and more than 1,300 square metres of frescoes. Chinese and foreign scholars regard it as the “museum of Oriental sculptures.” Courtesy https://www.buddhiststamp.com/
Notes:
Tang dynasty lineage & historical context: Set during China’s Tang Dynasty (618–907 CE), this encounter captures a turning point in the golden age of Chan (Zen) Buddhism. Tokusan (Deshan Xuanjian, 782–865 CE), a learned scholar devoted to traditional Buddhist scriptures, originally travelled south to challenge the rising Chan movement. Instead, his meeting with Master Ryutan (Longtan Chongxin) humbled him completely. Recorded in classic Tang-era chronicles like the Transmission of the Lamp, this famous tea exchange became one of Zen’s most enduring teaching stories (gong’an or koan).
Neuroscience and cognitive filtering: In modern cognitive psychology and neuroscience, the human brain constantly processes millions of bits of information per second but consciously filters them through established neural pathways and confirmation biases. This mental model mirrors Ryutan’s teaching: the brain naturally rejects or distorts novel data that contradicts existing frameworks, proving that intentional cognitive “emptying” or open-minded reflection is a biological and psychological prerequisite for paradigm-shifting learning.