The general idea put forth by the Palestinian side is that a person living in a certain place - for whatever reasons, for a certain amount of time - has some sort of claim of ownership to that place. In a general sense, I think we can agree that this is valid, all else being equal. On occasion, the Palestinians may reference the centuries-defunct claim of ownership conveyed by their connection to the ancient Philistines (who bear a nomenclatural resemblance to the Palestinians, but no more) but more often the claim is simply: "we lived there from [some time, say in 1800-1900] until 1948, when the Zionists kicked us out, we deserve to have our homes back." The factual nature of the first part of this statement seems to not be disputed too much. Yes, there were many Arabs, who now define themselves as Palestinians (or even did so then) who do not live currently in Israel proper. The second claim is the more controversial one.
Side note: when I say "Israel proper" a slight confusion may arise. This is partly due to my own ambivalence, and partly due to the long-standing ambivalence of the state of Israel itself. You see, technically speaking, with the exception of Jerusalem, Israel never formally annexed what is known as the "West Bank" in some circles, and "Judea and Samaria" in others. This land was last internationally recognized as the property of one single country back when the British owned it as part of the Palestine madate, up until 1947. Since then it was controlled by Jordan from 1948-1967, and by Israel from 1967-present, with certain parts of it under Palestinian control at various times. From 1967 until now, the Israeli government's attitude towards that territory has been a confusing one, alternately encouraging/supporting and discouraging/uprooting Jewish settlement in the area. The attitude of the Palestinians (for as long as one has been able to speak coherently of an entity called "the Palestinians") has generally been that they own the area, and like much (or all) of the current state of Israel, they should have jurisdiction and everything that goes along with that.
So now the basic question arises: what do various people or groups of people deserve, land-wise? It's the question not of what will make people happy, or what will stop violence on either side but what is fair. And this is where things get very, very complicated. Because on one hand, you have the Jews who claim some sort of ownership/connection to/sovereignty over the area as far back as King David, around the 10th century BCE. (Those claims are only disputed by arguing that those calling themselves Jews nowadays aren't the same group of people as those in King David's time. I don't think that this theory is really accepted by many, and besides, that starts getting into ideas about self-identification and group consistency that just muddle everything up further.) On the other hand, Arabs constituted the majority of the population of the Palestinian Mandate up until the Israeli War of Independence. Even though the gap in numbers between the Jewish and Arab populations was closing at that point, the Arabs were a majority. The British, for their part, see-sawed a lot between being pro-Jews and pro-Arabs, due to a long list of pressures from each side. Consequently, nowadays, Jews will point to the pro-Jews moments (e.g. the Balfour Declaration) and the Arabs will point to the pro-Arab moments (e.g. the 1939 White Paper). Let's be honest, this doesn't really get anyone anywhere.
Nevertheless, various historical ownership claims come into play in the public discourse about these issues (and basically any land dispute worldwide), so I thought it might be useful to kind of "zoom out" and categorize them:
1) Religious claim. This is very simple. It's usually some variation on the argument that God gave the land to one group or another, and therefore they deserve it. Needless to say, this argument doesn't really hold much water in modern diplomacy, the truth of the matter notwithstanding.
2) Ancestral claim. This argument says nothing about recent history, but claims that land is the ancestral property of a group. Somehow, it would seem, by living in a place for long enough, that place becomes ethnically 'owned' by that group, even if they are later displaced. It's kind of a "we were here first/longest" argument, as are a couple others in this list.
3) Demographic claim. This is what I hinted at above, when I discussed the demographics of the area prior to statehood and post-statehood. The argument is that based on self-determination ethics and such, the group that constitutes the majority should be in control of the area. Since both Jews and Arabs were the majority demographically at some point, each side easily brandishes this one.
4) Ownership claim. This is a slight variation on (3). It says that whichever group owns the most land (presumably under some mutually recognized rules for land ownership) should have control of the area.
5) Group ownership/sovereignty claim. I wasn't sure whether to separate these two, but decided to keep them together, because the idea that a group owns land is basically the same as saying that the group controls the land, and vice-versa. This argument claims that since the ethnic group at one point controlled the area and effective owned the land as a group, they should once more.
6) Third-party claim. This one argues that a third party that has some say about the fate of the area has bequeathed the area to one group or another. This argument would be the easiest to use in public discourse, due to the explicit written nature of the various declarations of the involved parties (usually the British Empire or the U.N.). However, problems arise from the simple fact that the various third parties contradict each other and themselves.
The main reason I'm going through all this is to get to one point, a point that I will expand upon in the follow-up to this post: the various historical claims can be made with various degrees of accuracy by both sides, and besides, history never forced anyone's hand. So the relevance (not the truth) of these claims to any attempts at peace-brokering is in question. Like I said, more next time.
Ok, so if you've made it this far, I'll acknowledge that this little essay (or whatever it is) wasn't constructed in the best manner, for many reasons. But if I took the time to go through and add in references and edit for structural coherence, etc, I probably wouldn't get around to posting it for a while. So I figure you can take this for what it's worth, and let the comments roll.