Hard as it is to believe, when Shoah survivors or their heirs try to recover artwork stolen by the Nazis, they too often run into a virtually insurmountable roadblock called "the art world."

It is a "world" literally unto its own. Whereas in almost any other segment of civilized society, stolen goods must be returned to those from whom they were stolen, the art world often contends that possession — whether of antiquities or a painting that once hung on the wall of your grandmother’s salon in Berlin — is tantamount to title.

Jewish organizations should be leading the charge for the recovery of Nazi-looted art, but they are not. Some of the biggest collectors of art and antiquities also are some of the biggest names in Jewish philanthropy. They write enormous checks for Jewish causes we hold dear and they get to dictate the Jewish response to art acquired under dubious circumstances.

Nine years ago, for example, New York County District Attorney Robert Morgenthau ordered the seizure of a painting by Egon Schiele, "Portrait of Wally," on loan at the time to the Museum of Modern Art from the Leopold Foundation in Austria. MoMA, chaired back then by Ronald S. Lauder, the single most important individual Jewish benefactor in Central and Eastern Europe, fought (and continues to fight) efforts to return "Wally" to the Bondi family, from whom it was stolen by the Nazis. Backing MoMA was the Jewish Museum, which is under the aegis of the Jewish Theological Seminary of America. (They argued, in essence, that the contracts governing art loans superseded the claims of Nazi victims.)

The latest flap, however, may be the most bizarre: The State of Israel recently passed legislation requiring all state institutions to turn over to a quasi-official company whatever heirless or unclaimed Holocaust-related assets are in their possession. The company in turn is to locate the owners and return the assets. It is unclear whether anyone realized when the law was passed that it also required the Israel Museum to turn over art in its possession that may have once belonged to Holocaust victims. The museum has never published a list of these art works (there are believed to be over 400 pieces); most are in storage because they are not considered "museum quality." "Museum quality" or no, the museum is fighting to keep the art for itself.

Halacha may be on the museum’s side.

Most of the rules relevant to property restitution flow from the Torah’s commandment about returning lost property, which would seem to be unconditional (see Deuteronomy ”:1-3), and the Talmud’s application of that commandment, which out of practical considerations is anything but absolute.

Of particular relevance is how the halacha deals with property that seemingly is irretrievably lost to everyone (such as an item that was carried away by the tide), coupled with what the owner believed to be true at the time of the loss.

This requires some explanation. A person who willfully holds on to property that he or she has found is a thief (provided, of course, that identifying the real owner is clearly a possibility). If the property was ownerless at the time that it was found, however, it is abandoned property and no theft attaches. If the person who lost the property concludes that it is lost forever and makes that conclusion known to others, that is abandonment (the halachic term is ye’ush); from that moment on, the property in question goes from being "lost" to being "abandoned."

Into this mix must be added the principle that a person instantly loses title to his or her property that is swept out to sea (property that is seemingly lost for all time). If it later washes up on the seashore, the finder has legal title to it even if it bears a mark identifying the previous owner.

What is not clear is whether this is due to ye’ush and, if so, whether it must be conscious abandonment. The Babylonian Talmud tractate Bava Metzia ‘4a-‘4b would seem to argue that it is a case of ye’ush. Maimonides, too, takes this position, as do some others. Still others, including the Shulchan Aruch, argue that ye’ush is neither assumed nor necessary in such cases because property swept out to sea is automatically considered "lost to everyone," which would seem to be the original position stated in the Talmud (ibid., BT Bava Metzia ”b).

Property seized by the Nazis in Germany may fall under this category. It could be assumed (although not all authorities do so) that the owner at some point abandoned all hope of ever seeing the property returned.

The same rule might apply to property seized in lands occupied by the Nazis, under ye’ush and/or under the principle that property seized by an invader becomes the property of the invader (why this is the case is also subject to a debate and who has title to the property depends on how the debate is resolved).

This principle of the transfer of ownership to a conqueror first finds expression in a discussion in BT Gittin 37b ff. While the issue there specifically deals with the acquisition of slaves, the application is to property in general. During the discussion, it is noted that the Babylonian scholar "Rav Papa said, ‘The territory of Ammon and Moab became purified through Sichon.’"

The Torah, in Deuteronomy 9, prohibits Israel from obtaining Moabite or Ammonite land. In Numbers ‘1:’6, however, the Amorite King Sichon is reported to have seized some Moabite territory. That act of conquest, says Rav Papa, automatically stripped Moab of its title to the land, which now belonged to the Amorites. It thus becomes fair game for Israelite conquest.

Following Rav Papa’s statement, the text in BT Gittin states that a non-Jew’s right of acquisition through conquest applies even to Jewish property. This would seem to preclude return of the art to its original owners.

On the other hand, in recent times, some authorities have qualified this right, saying that title to the seized property reverts to the original owner once the conqueror has been vanquished. This would seem to open a halachic door to returning the art.

Clearly, this is a very complex subject — this column has not even scratched the surface of the issues — and it cries out for definitive examination by competent authorities.

What should not need examination of any kind is the moral principle involved. Put succinctly in an interview with Ha’aretz by the new Israeli company’s legal adviser, "nobody holding victims’ property has the right to go on benefiting from it." That includes a museum that claims to be the "national museum" of the Jewish people.