Here's a one-liner I heard a few years ago: “There are two kinds of Jews – those who believe in tikkun olam and those who speak Hebrew.”Like most jokes, it’s serious in its own way.The oldest reference to tikkun olam (repairing the world) in the Jewish tradition is at the heart of the Rosh Hashana Additional Service ( musaf ), in the second half of the “ Aleynu ” (It is our duty) prayer, which dates from the 2nd century CE – “To fix the world by [establishing] the sovereignty of God.”But the term tikkun olam as it is used today is a modern one, “invented” – or resurrected and redefined – in the 1950s, apparently by Shlomo Bardin of the Brandeis Institute in California.Tikkun olam was then embraced as a central, organizing principle of Judaism first by the radical wing of Jewish progressives and then by the mainstream of the Reform movement.In the 21st century, tikkun olam has travelled farther, into the lexicon of US President Barack Obama and former president Bill Clin - ton, former UK chief rabbi Jonathan Sacks, and many others.The growing popularity of the phrase, which signifies, in its modern context, the centrality of Jewish responsibility to repair a broken world, has made tikkun olam a flashpoint for critics decrying a Judaism focused outwards, toward humanity as a whole. The criticism is encapsulated in one way of reading the joke; those who believe in tikkun olam are, inevitably, ignorant of the real language of Judaism. Conservative (little c) intellectuals such as Jack Wertheimer, Professor of American Jewish History at the Jewish Theological Seminary, and author Hillel Halkin have written acerbic attacks on the concept.“It al - ways fascinated me that “Jewish activists” have completely disregarded Judaism for activism,” Halkin has written, “and instead use Judaism as an excuse to justify their causes.”In an article in which he sardonically lists “The New Ten Commandments of the Jewish World,” Wertheimer has “I am the Lord Your God who brought you out of the land of Egypt in order to Repair the World” as the first “new” commandment.Quoting an unnamed “young Reform rabbi,” Wertheimer has him saying this: “Don’t keep kosher, that’s fine; don’t keep Shabbat, that’s fine; marry a non-Jew – whatever.But under - stand that it will take away your Jewish identity if you don’t fight for justice.”In short, the anti- tikkun folks argue, tikkun olam has become a conceptual tool for de-Judaizing Jewishness, a Trojan horse through which liberal or progressive ideas can infiltrate ostensibly Jewish frameworks and undermine their authenticity and autonomous value system – on faith in God, observance of the commandments, devotion to the Jewish people – from within. After all, they say, the historic sources of the phrase, including the one from the Rosh Hashana service, are about establishing the sovereignty of God, not fighting poverty and establishing justice.But that is where they are wrong. According to Judaism, you can’t seek God without pursuing justice for the poor and the oppressed because, in some pro - found way, God and justice are inseparable.The prophet Jeremiah expressed this in an astonishing and uncompromising way: “Pursue justice for the poor and the needy for that is what it means to know me.” Numerous passages in the prophets juxtapose rituals, including prayer, the Sabbath, and the holy temple to the commandment to create a society based on justice, equality and love. When push came to shove, guess what the prophets thought was more primary and indispensable? And while tikkun olam may be, in its modern usage, amorphous, and more popular among American Reform than Israeli Orthodox, perhaps the greatest figure in 20th century Orthodoxy, Rabbi Abraham Isaac Kook, had this to say about God and social justice: “We do not regret that a quality of social justice can be built without any spark or mention of the divine, because we know that the very aspiration to “tzedek” (justice), in whatever form, is itself the brightest possible divine influence.”Kook is far from the only Jewish luminary of the first half of the 20th century who emphasized social justice, and criticized inequality and greed.But the past 70 years have seen the social justice agenda with - er away on the Orthodox vine – and thus in the religious consciousness of most Israelis. So, the other way to read the joke is that it is poking fun at Israelis and the Orthodox – overlapping groups whose entire membership know Hebrew, but whose Judaism has been left largely bereft of tikkun olam .It’s high time to heal this split. Those who believe in tikkun olam will find unexpected treasures of inspiration and insight by delving deeper into a tradition that has penetrating resources that can guide a precise critique of contemporary economic and environmental injustice.And those who know Hebrew would do well to open their eyes and see the intellectual foundations and spiritual longing for a more just and beautiful world that has always been the soul of Judaism.