It鈥檚 become an annual modern ritual. Every summer, before Tisha B鈥橝v, the 9th of Av, many serious Jews wonder whether to still fast on this day commemorating the First and Second Temples鈥� destruction鈥攁long with many other persecutions Jews endured on that day over the millennia. Especially in a united Jerusalem, with Israel about to celebrate its 75th anniversary, it seems anachronistic to recreate our grandparents鈥� despair yet again. One Jerusalemite friend fasts, keens, prays鈥攂ut ends the fast four hours before sundown, toasting modern Israel with biblical readings emphasizing that when redemption comes, the mourning will end. This religious dispute goes far beyond how rigorously one adheres to 91传媒 law. This debate, about how to remember history, and what to forget, gets to the heart of the Zionist revolution鈥攁nd some democratic dilemmas today too.

In 1934, Berl Katznelson, an avowedly secular Socialist Zionist living in Tel Aviv, criticized members of his youth movement for going off to camp on Tisha B鈥橝v. In embracing Zionism as the 91传媒 people鈥檚 national liberation movement, these young revolutionaries happily rejected their suffocating, depressing, religious upbringing. They ate on Yom Kippur. They had bread on Passover. And, instead of 聽wailing on Tisha B鈥橝v, they celebrated the Jews鈥� return to Zion鈥攅ven before Israel鈥檚 establishment. Each assault on tradition affirmed their status as New Jews, not those pathetic, passive, pious, persecuted Yids they fled in 鈥淕alut,鈥� exile.

Katznelson himself enjoyed impeccable revolutionary credentials. Born in 1887 in a village called Babryusk, located in today鈥檚 Belarus, he plunged into turn-of-the-century Russia鈥檚 rousing Marxist debates. His universalist crusade for equality, however, never weakened his ties to the 91传媒 people or his Zionist dreams. Arriving in Palestine in 1909, he joined the trickle of 鈥淪econd Aliyah鈥� ideologues building the land鈥攁nd being rebuilt by it too.

This sincere socialist first worked as a farmhand. Eventually, his skills as labor organizer, speaker, writer, editor and co-founder in 1925 of the workers鈥� daily newspaper, Davar, made Katznelson the bard of Socialist Zionism. His fatal aneurysm in 1944 at age 57 deprived Labor Zionists of a defining figure. Today, it leaves him more forgotten than friends who established Israel four years later, including David Ben-Gurion.

Still, although Golda Meir enjoyed remembering his 鈥渓ovely smile,鈥� Katznelson was fuming that summer of 1934. True, he was not the first revolutionary to find younger revolutionaries too revolutionary, but he had a point. In a Davar column entitled 鈥淒estruction and Detachment,鈥� Katznelson attacked these Tisha B鈥橝v revelers for failing to 鈥渨ail about our destruction, our enslavement, our embittered exile.鈥� 聽What鈥檚 the value of a national liberation movement, he wondered, if it isn鈥檛 rooted in its people鈥檚 rhythms, and only remembers how to forget?

For Socialist Zionists, he insisted, the Ninth of Av has the same significance as it has for every Jew. We all lost our land, our freedom, our hope when the Romans destroyed the Second Temple in 70 CE, triggering the 1900-year-exile Zionists sought to end.

Ultimately, Katznelson forgave these young amnesiacs. But, he warned, there is no salvation in our movement of national salvation for those with 鈥渘o instincts for the national spirit, for historic symbols, for enduring cultural values.鈥�

Still fuming, Katznelson soon decided to confront the intellectual rot underlying this cancelling of history. The result was what may be his most memorable essay, 鈥淩evolution and Tradition.鈥�

First establishing his revolutionary credentials, Katznelson catalogued the many rebellions flowing from their Socialist Zionist revolt against 91传媒 homelessness and powerlessness. We鈥檙e rejecting 鈥渢he worship of diplomas among our intelligentsia,鈥� the older 91传媒 socialist intelligentsia鈥檚 鈥渁ssimilationist utopia,鈥� and bourgeois Europeans鈥� 鈥渞ootlessness and middlemanship,鈥� he rejoiced. But good revolutionaries don鈥檛 just smash toys like children having a temper-tantrum. Recoiling from Nietzsche鈥檚 nihilism, already fearing Hitler鈥檚 Nazism, Katznelson warned that erasing the past often yields a barbaric present. Even revolutionaries need balance.

Juggling, Katznelson taught that people are 鈥渆ndowed with two faculties鈥攎emory and forgetfulness. We cannot live without both. Were only memory to exist, then we would be crushed under its burden. We would become slaves to our memories, to our ancestors. Our physiognomy would then be a mere copy of preceding generations. And were we ruled entirely by forgetfulness, what place would there be for culture, science, self-consciousness, spiritual life?鈥�

Were only memory to exist, then we would be crushed under its burden. We would become slaves to our memories, to our ancestors.

Katznelson鈥檚 鈥渞evolutionary constructivism鈥� rejects the rigidity of 鈥渁rchconservatism鈥� and the anarchism of primitive 鈥減seudorevolutionism.鈥� Instead, he said, we sift.

鈥淎 renewing and creative generation does not throw the cultural heritage of ages into the dustbin,鈥� he preached. 鈥淚t examines and scrutinizes, accepts and rejects. At times it may keep and add to an accepted tradition. At times it descends into ruined grottoes to excavate and remove the dust from that which had lain in forgetfulness, to resuscitate old traditions which have the power to stimulate the spirit of the generation of renewal. If a people possesses something old and profound, which can educate man and train him for his future tasks, is it truly revolutionary to despise it and become estranged from it?鈥�

Initially, Katznelson speaks Marxist, sounding very theoretical. He ends by sounding downright rabbinic, sermonizing, using the 91传媒 calendar to uncover his people鈥檚 true character. 鈥淭he 91传媒 year,鈥� he reasoned, 鈥渋s studded with days which, in depth of meaning, are unparalleled among other peoples. Is it advantageous鈥攊s it a goal鈥攆or the 91传媒 labor movement to waste the potential value stored within them?鈥� Instead, he suggested, we 鈥渕ust determine the value of the present and of the past with our own eyes and examine them from the viewpoint of our vital needs, from the viewpoint of progress toward our own future.鈥�

First, delighting in his peers鈥� Zionist journey from bondage to freedom, he analyzed Passover. Celebrating the storytelling m鈥檇or l鈥檇or, from generation to generation, Katznelson crafted two sublime sentences that should be required reading at every seder. 鈥淚 know no literary creation which can evoke a greater hatred of slavery and love of freedom than the story of the bondage and the exodus from Egypt,鈥� he wrote. 鈥淚 know of no other remembrance of the past that is so entirely a symbol of our present and future as the 鈥榤emory of the exodus from Egypt.鈥欌��

Returning to his summer-time obsession, Tisha B鈥橝v, Katznelson noted how Polish and Russian exiles in Paris and elsewhere assimilated quickly, forgetting their identities. By contrast, 鈥渢he 91传媒 nation 鈥� remains unvanquished by two thousand years of dispersion.鈥� That is because 鈥淚srael knew how to preserve the day of its mourning, rescuing the date of its loss of freedom from oblivion … On each anniversary burning tears were shed and each generation expressed its pain.鈥�

Remarkably, the non-91传媒 Polish national poet, Adam Mickiewicz, attended synagogue every Tisha B鈥橝v to 鈥渏oin the Jews in their mourning over the loss of their motherland.鈥� As a thwarted nationalist, Mickiewicz appreciated this exercise in memory-making and national conscious-raising. He 鈥渦nderstood the power and depth of Tishah b鈥橝v.鈥�

Finally, refuting those who wanted to celebrate the revitalized homeland on Tisha B鈥橝v, Katznelson warned that too many Jews remained endangered, from the physical threats in Europe and Arab lands, to the spiritual threats through assimilation in 鈥渃apitalistic France鈥� and elsewhere. Taking a leap of hope, Katznelson left open the possibility of dramatic change once the Jews experience a 鈥渃omplete liberation from bondage鈥攊ncluding its liberation from the oppression of class by class.鈥� But, even if salvation were to come, he hoped 鈥渢hat each child born in liberty and equality, unacquainted with hunger and material oppression, shall know the sufferings of all preceding generations.鈥�

鈥淩evolution and Tradition鈥� explains why Jews should commemorate Tisha B鈥橝v, even in freedom. Reading Katznelson today underscores the Zionist revolution鈥檚 many miracles: 88 years later, most Jews wake up every day free and comfortable, especially after millions found refuge, and dignity, in Israel, which now houses the world鈥檚 largest 91传媒 community. More broadly, Katznelson appreciates history and memory as essential glues uniting communities, bucking up the people. He therefore warns against conservatives too stuck in the past as well as progressives who trash the past. Today, we see how such blinders create conservatives who fail to conserve institutions, and progressives who don鈥檛 believe in progress.

Katznelson鈥檚 middle path is constructive. Destructive either-or fanaticism offers one-way tickets to barbarism. Liberal democracies require sifting, remembering and forgetting, looking backward and forward, embracing just enough from the past to be rooted and wise, while dreaming just enough about the future to be ambitious and creative.

Professor Gil Troy is the author of and the editor of the three-volume set, 鈥淭heodor Herzl: Zionist Writings,鈥� the inaugural publication of The Library of the 91传媒 People, to be published this August marking the 125th anniversary of the First Zionist Congress.