Yoel Finkelman’s enviable job is part detective, part collector, part teacher — and almost entirely enjoyable.

The affable Dr Finkelman is the curator of the Haim and Hanna Solomon Judaica Collection at the National Library of Israel. It means, effectively, that he is in charge of the largest collection of Judaica in the world —Jewish texts, haggadot, ketubot, Jewish music and sound, Jewish manuscripts, ephemera and much more.

In this role the Detroit-born Dr Finkelman gets to bid at auction for the rare and the not-so-rare, to negotiate with antique dealers or “merchants”, and to sift, lovingly, through thousands of artefacts and pages, representing Jewish voices and culture, in many languages, throughout the ages.

In fact, the National Library of Israel (NLI) comprises four separate collections; Israel, Judaica, Islam and the Middle East, and the humanities.

Among its gems are significant handwritten works by Maimonides and Sir Isaac Newton, exquisite Islamic manuscripts dating back to the 9th century, and the personal archives of leading cultural and intellectual figures including theologian Martin Buber, the former Prisoner of Zion Natan Sharansky and the beloved Jerusalem of Gold singer, Naomi Shemer.

Dr Finkelman, an academic who formerly lectured at Bar-Ilan University in Tel Aviv, has been in the post for five years.

Doing this work, he freely admits, “came as a bit of a surprise — this is not where I thought I would be. But I was interested in the renewal plan of the National Library”.

The 125-year-old institution is moving to a purpose-built building next to the Knesset in 2021, “and part of that plan was to bring in curators who were not from a strict library background. Our task is to be more of the voice of the user, but from the inside. We already have a lot of librarians; it’s healthy to have other voices who have been trained in other disciplines”.

He was already a user of the NLI before he went to work there: “There is no-one in the field of Jewish studies in Israel who is not, in some form or other, a reader at the library. I spent a long time when I was doing my dissertation, in the reading room. It’s a central place.”

But Dr Finkelman says that the sheer breadth of what is available at the NLI is not immediately apparent to the casual user. “When you are a user, you have everything on a silver platter.

You are interested in a specific area, you order it, you read it. But because the readership is so diverse, you have people researching everything from the oldest manuscripts in existence to contemporary children’s literature and everything in between”.

The sheer breadth of the collection, he says, presents a huge challenge for the curator. “How do we make good decisions, and have good institutions in place to be collecting, in such a diverse set of languages, genres, literary and physical forms?”

And the NLI staff must also learn to recognise when and where there are gaps in their collections. “Our staff have a very good working knowledge and if you see a lot of auction catalogues, or you work with certain suppliers or sellers or merchants, then you begin to notice patterns.

So if, for example, it’s a 19th century Eastern European edition of rabbinic text [for sale], I’m pretty confident that we have it; and if it’s Soviet-era Yiddish, I’m pretty sure we don’t.” The reason?

“It’s absolutely natural that the world of Jewish studies scholars would have their hands on European rabbinics. But Soviet-era Yiddish, because of historical developments, is very rare.”

His job, Dr Finkelman acknowledges, has a certain amount “of serendipity. It can happen that a donation from a significant collector will make a difference in how our collection develops.”

But he is aware of limits on what the NLI already holds. They have, he says, a reasonably good collection relating to India, but he would not be surprised if there was a lot missing. Similarly there are limitations in the collection when, for example, “items were issued in very limited quantities, such as newspapers in the DP (displaced person) camps. In fact, the Second World War as a whole means there are a lot of gaps.”

Every curator for each of the NLI’s collections has a 100-page “collectors’ development policy” which delineates what does and does not qualify to be included in the library.

“For the Judaica collection, that tries to be as expansive as possible. So if it is a published work by and about Jews or Judaism, which reflects directly on Jewish life across geographical boundaries or the course of history, then that’s something that we want to make a reasonable effort to acquire.

When it comes to manuscripts, or rare books, or archives, where there’s no realistic possibility of acquiring everything, then we try to prioritise. We have to decide to what extent we can compete with the budgets of other, private institutions.”

There are fewer question marks, says Dr Finkelman, over what constitutes something worthy of inclusion in the Judaica collection when it comes to the pre-modern world.

“Jews [in the pre-modern world] perceived themselves as separate and different from the environment around them — and what they did and produced will have been infused with the essence of Jews and Judaism.

“Once you get to the modern world, and the possibilities of social and intellectual integration with the wider community, it is more complex.”

So for Jews in the modern world, Dr Finkelman and his team judge by whether it can be said that the person’s work has significant Jewish content. “Is their Judaism significant or representative in their work?

“So, take a figure like Philip Roth, the contents of whose novels are filled with Jews and Judaism. And compare him to an author who is biologically and halachically Jewish, and whose novels are not.”

At the end of the day the choices are much easier than one might think about what the NLI should buy.

“Let’s say [the choice is between] a first draft of Portnoy’s Complaint, and the significance for the research world is that it will give us a window into his work and editing processes, and how and early draft differs from the published draft, and what that says about how Roth originally envisioned this work… and on the other hand, there is a Mel Brooks’ Borscht Belt script, which is identical in every way to what is ultimately performed.

"Well, to put it in a very crude way, what we do is dictated by a simple mathematical formula. How much knowledge per dollar does our purchase get us?”

In other words, Dr Finkelman says, what he acquires for the Judaica collection has to be “reflective of the Jewish experience”, and should also not duplicate holdings the library already has.

He terms his post “the coolest job in the world”, and has two serious recent acquisitions competing for his favourite in the collection.

One is pages from the Afghan Geniza, and the other is a hefty 80 per cent of the extraordinary library amassed by the late London collector, Jack Lunzer — the Valmadonna Trust.

The NLI has acquired 250 pages from the Afghan Geniza, one of the most exciting purchases in the library, says Dr Finkelman.

“There are pages in Hebrew, in Judeo-Persian, in regular Persian, from the Silk Road prior to the Mongol invasions in the 13th century. And you have 11th century documents relating to the family archive of a man called Abu Nasr Ben Daniel, a Jewish landowner who was the patriarch of a Jewish family in the town of Bamyan. There are personal letters, and business letters, and an accounts book.”

For Dr Finkelman, the biggest kick was finding that one of the pages was a passage from the Mishnah, significant to scholars because they did not know how far the Mishnah had travelled geographically, in the mediaeval world — and significant to him because it was the same passage he had been studying with his own son in the week of the acquisition.

“It may be a cliché, but it really was the sense of someone waving to you from history, a feeling that you can touch the past.”

Mr Lunzer was an extraordinary collector, says Dr Finkelman. The NLI already owned quite a lot of Anglo-Jewish documents and manuscripts besides the Valmadonna hoard, but its material, some dating from the earliest days of printing in London, is now a jewel in the Judaica crown at the NLI.

Dr Finkelman’s aim, now, is to get even more of his extraordinary collection digitised so that researchers all over the world can gain access to his library’s treasures.

He is aware of the often-referred to “crisis in Jewish literacy”, but notes with great good humour and optimism that “if you come into our reading room any later than 9.30 in the morning, there are no seats left”.