If you know any­thing at all about Zen, you know the famous ques­tion about the sound of one hand clap­ping. While the brain teas­er did indeed orig­i­nate with a Zen mas­ter, it does not ful­ly rep­re­sent the nature of the koan. Between the 9th and 13th cen­turies, when Chan Bud­dhism, as Zen was known in Chi­na, flour­ished, koans became wide­ly-used, explains the TED-Ed ani­mat­ed video above, as objects of med­i­ta­tion. “A col­lec­tion of rough­ly one thou­sand, sev­en hun­dred bewil­der­ing philo­soph­i­cal thought exper­i­ments,” koans were osten­si­bly tools to prac­tice liv­ing with the unex­plain­able mys­ter­ies of exis­tence.

The name, notes the les­son, “orig­i­nal­ly gong-an in Chi­nese, trans­lates to ‘pub­lic record or case.’ But unlike real-world court cas­es, koans were inten­tion­al­ly incom­pre­hen­si­ble.” Koans are “Sur­pris­ing, sur­re­al, and fre­quent­ly con­tra­dict­ed them­selves.” The lessons in ambi­gu­i­ty and para­dox have their ana­logue, per­haps, in cer­tain trains of thought in Medieval Catholic phi­los­o­phy or the ide­al­ism of thinkers like George Berke­ley, who might have first come up with the one about the tree falling in the for­est.

But is the pur­pose of the koan sim­ply to break the brain’s reliance on rea­son? It was cer­tain­ly used this way. Zen Mas­ter Eihei Dogen, founder of Japan­ese Soto Zen trav­eled to Chi­na to study under the Chan Mas­ters, and lat­er crit­i­cized this kind of koan prac­tice and oth­er aspects of Chan, though he also col­lect­ed 300 koans him­self and they became inte­gral to Soto tra­di­tion. Koans are not just absur­dist zingers, they are, as the name says, cases—little sto­ries, often about two monks in some kind of teacher and stu­dent rela­tion­ship. Many of the stu­dents and teach­ers in these sto­ries were patri­archs of Chan.

Like the say­ings and doings of oth­er reli­gious patri­archs in oth­er world reli­gions, these “cas­es” have been col­lect­ed with copi­ous com­men­tary in books like The Blue Cliff Record and The Book of Seren­i­ty. They show in snap­shots the trans­mis­sion of the teach­ing direct­ly from teacher to stu­dent, rather than through sacred texts or rit­u­als (hun­dreds of koans, rules, and rit­u­als notwith­stand­ing). That they are puz­zling and ambigu­ous does not mean they are incom­pre­hen­si­ble. Many seem more or less like fables, such as the oft-told sto­ry of the monk who car­ries a beau­ti­ful woman across a mud patch, then chas­tis­es his younger com­pan­ion for bring­ing it up miles down the road.

Oth­er koans are like Greek philo­soph­i­cal dia­logues in minia­ture, such as the sto­ry in which two monks argue about the nature of a flag wav­ing in the wind. A third steps in, Socrates-like, with a seem­ing­ly “right” answer that tran­scends both of their posi­tions. The longevi­ty of these vignettes lies in their subtlety—surface mean­ings only hint at what the sto­ries are up to. Koans force those who take up their study to strug­gle with uncer­tain­ty and irres­o­lu­tion. They also fre­quent­ly under­mine the most com­mon expec­ta­tion that the teacher knows best.

Often posed as a kind of oblique ver­bal com­bat between teacher and stu­dent, koans include extreme­ly harsh, even vio­lent teach­ers, or teach­ers who seem to admit defeat, tac­it­ly or oth­er­wise, when a stu­dent gets the upper hand, or when both con­front the speech­less awe of not know­ing. Atti­tudes of respect, rev­er­ence, humil­i­ty, can­dor, and good humor pre­vail. Per­haps under all koan prac­tice lies the idea of skill­ful means—the appro­pri­ate action to take in the moment, which can only be known in the moment.

In his short, humor­ous dis­cus­sion of Zen koans above, Alan Watts tells the sto­ry of a Zen stu­dent who tricks his mas­ter and hits him with his own stick. The mas­ter responds with approval of the student’s tac­tics, but the koan does not sug­gest that every­one should do the same. That, as Dogen would argue, would be to have an idea about real­i­ty, rather than a whol­ly-engaged response to it. What­ev­er else koans show their stu­dents, they point again and again to this cen­tral human dilem­ma of think­ing about living—in the past, present, or future—versus actu­al­ly expe­ri­enc­ing our lives.

Relat­ed Con­tent:

Alan Watts Presents a 15-Minute Guid­ed Med­i­ta­tion: A Time-Test­ed Way to Stop Think­ing About Think­ing

Take Harvard’s Intro­duc­to­ry Course on Bud­dhism, One of Five World Reli­gions Class­es Offered Free Online

The World’s Largest Col­lec­tion of Tibetan Bud­dhist Lit­er­a­ture Now Online

Josh Jones is a writer and musi­cian based in Durham, NC. Fol­low him