For many readers of this magazine, the difficult word in the title is probably the second. The word socialism is so little heard today, it seems to hark back to another era, of flying pickets, composite motions, beer and sandwiches at number 10. Even on the far-left most young revolutionaries prefer to call themselves 'anti-capitalist'. But for me, the more difficult word is the first. What constitutes a Jewish socialist, and more to the point, do I get in?

Seeing members of my family this spring, conversation turned to the first signs of an old fear. One aunt, Carole complained that her partner had become an anti-Semite. Another relative Margaret perked up, 'mine too'. Her theory was that Sharon was to blame for making the position of Jewish people vulnerable. One aunt spoke up for 'plucky little Israel'. A week earlier, some 20,000 Jewish demonstrators had marched the old route of the left from Hyde Park to Trafalgar Square. Tribune called it a 'peace rally', but given that one speaker Benjamin Netanyahu has been calling for the state murder of Yasser Arafat, the term seems generous. The march was called on the basis of two slogans - defend Israel and fight anti-Semitism. The latter slogan fitted with what the people on the march thought. Something more than just long-standing anxiety was at stake.

Meanwhile, writing in the Guardian, chief Rabbi Jonathan Sacks has accused anti-Zionist campaigners of paving the way for anti-Semitism. It is brutal claim, one aimed most pointedly at Jews on the non-Zionist left. The old taunt, 'self-hating Jew', has also reappeared again in recent several debates. I was in New York last spring to hear it levelled against Noam Chomsky, and in London this year to hear the same.

For the record, I was bought up in a multi-faith environment, and reached adolescence without identifying with religion. My father was born Anglican, converted to Catholicism and has been for years a Buddhist. My mother's parents were Jews, who lived in Austria before the war and escaped in 1938. Family stories told how my grandparents Kurt and Olga fled Vienna. As they left Austria their few valuables were sewn - to avoid capture - on the underside of the train seats. Determined not to stand out, their children were sent to Christian schools in Melbourne, their only religious upbringing being occasional discussions with their parents' overwhelmingly-Jewish friends. My own education was the equivalent of my mother's translated from 1950s Melbourne to 1970s London. I did not have a barmitzvah and I have not once knowingly stood inside a synagogue.

But if the Jewish religion is irrelevant to me, then why have I described myself as a Jew? As a child, my aunt did not hesitate to explain to me that any value I had in society came solely as a product of my Jewish parentage. She told me that this quality was heritable and divisible, but not infinitely so. I might be half-Jewish, but there was no such thing as a quarter-Jew. Minor fractions, quarters, eighths and sixteenths were not allowed. If I failed to marry someone of my grandparents' religion, then my child could not be Jewish. I will confess that this approach always seemed odd to me, and my later knowledge of the convoluted attempts in the 1930s to isolate a separate Jewish 'race', have left me suspicious of all theories in which race plays more than a minor role.

            If not race, and not religion, what else marked me out? Where did it come from, this magical quality of being-a-Jew? For my cousins, the best evidence of their devotion to Judaism has been a loyalty to the Jewish state in Israel. All three have spent holidays working in a kibbutz, all know Jerusalem well. Yet personally I dislike oppression in all forms, and Israel has never been a positive example to me. When I first had the chance to visit the Middle East, during a two-month holiday in summer 1994, Palestine took precisely three days. One day was enough to take in the wealth of Jerusalem, another for the West Bank, the third day was spent under the scrutiny of teenage Israeli soldiers after my partner and I attempted to make the overland crossing to Egypt at Rafah. Alongside us the Palestinians were treated like animals, some were allowed through, others stopped without reason. Soldiers made the people crossing wave their passports in the air, so that their papers could be checked without the soldiers coming close. All were laughed at, all were made to wait for hours. One young soldier asked me, why are you with them? For me and my partner, this brief visit marked the point at which a dislike of injustice taking place in another country of which we knew little, became a living contempt for a racist state.

            Through my teens and early twenties, I looked for left-wing models, people who had already worked out their own solution to the problem of being a secular Jew. Those of my heroes who were Jewish, seemed to have the least to say about identity - neither Luxemburg nor Trotsky considered what made them Jews. Friends advised me to read Albert Einstein. In his famous saying, 'God does not play dice', God was a code for the laws of physics, which were rational, simple and open to human understanding. His divinity was the God of the Dutch philosopher Spinoza, 'the God who is nature'. Apart also from his occasional admiration for the Old Testament prophet Moses, Albert Einstein was otherwise an agnostic. In the absence of a religious test of Jewishness, Einstein fell back on the common sense and cultural definition that many others of his generation also adopted. Jews were those who shared a common culture, originating in religion but transcending it.

Reading Einstein, it became clear to me that in the conditions of the inter-war crisis, this cultural definition became in practice ever more vague. With Hitler and anti-semitism both on the rise, in such a time when a self-definition was absolutely necessary, a Jew was anyone considered by his enemies to be a Jew. This was the same definition of Jewishness adopted by non-Jewish students in France '68. When Daniel Cohn-Bendit was attacked by the French right as a foreigner, supporters responded in the street, 'We are all German Jews'. Arguing with another Jewish Socialist (calling him a Socialist-Zionist would capture his politics better) in Oxford in 1995, I repeated this point - let the racists worry about what makes a Jew. He was shocked, and I was less convinced afterwards.

            Taking up the theme of enmity, David Ceserani has suggested that the experience of suffering has become the litmus test of contemporary Jewishness. Caesarani points out that the most common reason which Jews are given to identify ourselves as Jews is the Holocaust. Certainly this point was made throughout my childhood, any disobedience of maternal injunctions could raise the reply, 'Remember what the Germans did'. It was always the Germans - never some Germans - as if the children and grandchildren of murders, should continue to shoulder the blame for generations to come. No doubt some of this lesson rubbed off. Loyalty to my grandparents and their generation is for me still an absolute ethical rule. It is an injunction to loyalty which I do not feel for the memory of my father's parents, traditional rural English, and Tories to boot. I remember again in 1995, an attempt by my college student union to commemorate the Holocaust. When the proposal was made that the memorial should be sited in the college chapel, that was enough to bring me to tears. Is that memory of shame and hurt enough to define me a Jew?

            I worry that the Holocaust has become the touchstone of contemporary Jewishness. To create an identity on the basis of suffering is a route to create only further suffering. For Theodore Herzl and the early Zionists, the terrible experience of the diaspora was ample justification for return. The evils of one historical situation justified a peculiar vengeance, which was met on a different people and at a different time. The result was the dispossession of an innocent party, the Arab Palestinians. The logic of an overwhelming fixation on Holocaust is to repeat the blood sacrifice that undid the trauma of the gas chambers. But that Arab sacrifice has been a terrible crime indeed. Any attempt to create a social identity based on suffering must act to stunt the humanity of those who adopt that identity. The need to live implies at some stage a need to move on.

            If neither religion nor race, not Israel and not the Holocaust, then what makes me define myself as Jewish? The best reason I've found for calling myself a Jew is contained in a poem written by Mike Rosen, 'I am a Jew because my mother and father told me I was / I am a Jew because I don't believe in God / I am a Jew because I am told not to be so Jewish ... I am a Jew because I am looking forward to the time when there will be no high places.' The identity here is more about socialism than religion. It leads necessarily to support for the Palestinians in the current conflict. A cultural loyalty, an arbitrary feeling, a loose identification with a historical people, a vague social memory with no basis in contemporary fact - if that's the best identity I've found, I'll live with it.

From Jewish Socialist, spring 2003