Derived from the Chinese term for a public announcement and particularly associated with the Rinzai sect, FTP, these are which paradoxical statements or questions intended to exhaust the rational intellect, a well-known example of which is the sound of one hand clapping.
They are collected in the 1228 compilation Mumon-kan and the 1125 "Blue Cliff Records" of Y?an-wu.  Dogen, the founder of the Soto school of Buddhism, apparently utilized them, even though his school espoused the method of "just sitting" in order to achieve the desired effect of the "sloughing off of the mind."  Derived from the Chinese term for a public announcement and particularly associated with the Rinzai sect, FTP, these are which paradoxical statements or questions intended to exhaust the rational intellect, a well-known example of which is the sound of one hand clapping.
They are collected in the 1228 compilation Mumon-kan and the 1125 "Blue Cliff Records" of Y?an-wu.  
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