Last month, in the district court of Tel Aviv, a blow was struck for common sense. Although in itself a small matter, concerning the personal circumstances of one Israeli citizen, the court's verdict is likely to have profound repercussions, touching not merely the legal status of Jewish citizens of the Jewish state but also the Jewish character and characteristics of that state, matters which currently lie - as we all know - at the very heart of Israel's relations with the Arab world.

On September 27, the Tel Aviv district court upheld an application made by Yoram Kaniuk to have his status on Israel's population register defined as Jewish by nationality but not by religion.

The Interior Ministry, which maintains the register, will now have to redefine him as being Jewish, but "without religion".

Mr Kaniuk, a much acclaimed writer of both fiction and non-fiction, was born in Tel Aviv's Neve Tzedek district 81 years ago. He fought for the Palmach in Israel's war of independence in 1948 and was wounded in action.

He married a Christian lady. He and his family apparently practise no religious observance. Yet he is a proud Jew.

In Tel Aviv, a blow was struck for common sense

While not for one moment wishing to interfere with the right of other Jews to freedom of worship, his lawyer explained to the court that as Kaniuk himself chooses to live a life devoid of religious belief, he resents - and views as an infringement of his own rights - the Interior Ministry's insistence that he be described as "of the Jewish religion". Now that description will have to be amended.

I have never met Mr Kaniuk. If I did, I would feel obliged to tell him that - as a fellow Jew and Zionist - I find some of his published views (on, for example, the future status of Jerusalem) unpalatable and unacceptable.

I would also feel obliged to tell him that I wish he had found a Jewish lady to marry instead of a Christian one. But I would also feel duty bound to add that, in insisting on defining himself as Jewish simply and exclusively by nationality (the Hebrew word he uses - le'om - can also be translated as ethnicity) he has earned my admiration and has my unqualified support.

The quality of being Jewish has two interrelated but essentially distinct dimensions, one religious and the other ethnic. While following a Jewish religious lifestyle might indeed reflect or be grounded in a Jewish ethnic identity, the second does not necessarily follow from the first.

In this country - as in Israel - there are many Jews who are irreligious, even anti-religious. But they are still Jews and willingly identify themselves as such. In the eyes of UK law, Jews are an ethnic group, and therefore enjoy the protection afforded by race-relations legislation.

It was, after all, on that basis that the child "M" was famously able to bring and eventually win his case against the JFS and the Office of the Chief Rabbi in 2009.

In Israel, the Kaniuk case has focused public attention on, and re-ignited the debate about, the relationship between "church" and state. Israel's declaration of independence purported to guarantee freedom of religion, but the paradoxical truth is that for Jews, in Israel, such a freedom does not currently exist.

In Israel, the Orthodox rabbinate enjoys - or has until very recently enjoyed - a state-sanctioned monopoly as far as the personal status of Israeli Jews is concerned.

As an Orthodox Jew myself - Jewish both by observance and by ethnicity - I find this deeply troubling. I also suspect that it is counter-productive, alienating from any religious observance those Israeli Jews who might otherwise consider adopting some form of religious lifestyle. I know many rabbis, some of whom you would probably consider not just Orthodox but ultra-Orthodox, who share this view.

Religious identity and belief are essentially private matters, in which the state should play no part, other than to act as their guarantor.

But it is not just on Israel's domestic front that the Kaniuk judgment is likely to create waves. As Benjamin Netanyahu explained so eloquently when addressing the UN last month, at the core of the dispute between Israel and its Palestinian-Arab neighbours is the refusal of the Palestinian Authority to recognise Israel as a Jewish state.

This denial has religious origins, but is commonly articulated, nowadays, in terms of a refusal to accord Jews the status of a nation with a concomitant right of national self-determination.

In emphasising the ethnic dimension to what one might term Jewish "peoplehood" Yoram Kaniuk's victory could not have come at a better time.