Palestine as an independent nation-state – that is, governed by its own elected people, and not as a colony – did not exist before 1948. Neither of course, did Israel, which became a nation-state when it declared its independence and Britain dissolved its holdings over Mandatory Palestine (the “midnight on May 14/15” that one of your quotes refers to). However I am sure you were looking for more than a 2 sentence answer, so really the issue here is, what do people mean when they assert Palestine did/did not exist before 1948? Taken literally, of course no independent nation state existed in the land between the Mediterranean Ocean and the Jordan River before 1948, because nation-states with distinct national borders only became a political reality a few centuries ago, and a reality in the Middle East and Arab World in the first half of the twentieth century. However, Palestinians as a people, tied to specific places within what the British designated as “Mandatory Palestine,” and Palestinian nationalism both existed before 1948. This question doesn’t specifically ask about the history of Palestinian nationalism, nor about the history of when the region under discussion was called “Palestine” (which various parts of it have been in various ways over millenia), however, so I will leave it there for now.

Did it exist as a term? Yes.

Did it exist as an independent state? No.

I don't think either of those conflict, however. The first is referring to the fact that "Palestine" was not a state before 1948. The latter is saying that Palestine as a state exists now, despite not having been an independent state before 1948.

I think this is therefore a question based on a misunderstanding of two comments which agree with the indisputable historical fact that there has never been an independent state of Palestine, insofar as I am aware. Whether it exists as a state now is a political question that I will not get into, because it implicates things within the past 20 years. What I can say is that the Palestinian declaration of independence by the Palestine Liberation Organization (the main Palestinian umbrella group, though it has long been largely run by Fatah, which has been opposed by Hamas, and Hamas is not a member of the PLO) claiming that statehood was made in 1988, which should give you some indication that Palestinians view their independent statehood as post-1948 as well.

This does not mean Palestinians as a national group arose in 1988, by the way. Think of the Kurds; they don't have a state but want a state, by some claims, and have made claims as a national group. So Palestinians can exist even without an independent Palestinian state.

I've done my best to stick to the question but am happy to expand if necessary!

I know this server doesn't allow short answers but there is only one answer.

Palestine as a region existed for 2000 years, not to be confused with Philistia where the root of the name came from, but not directly from them but probably because of them. You see, the term became popular during the travels of Herodotus in which he named Canaan to Palestine.

The Roman Empire, after the Bar Kohva revolt, renamed the land to Syria- Palestina. The reason is debated, some say it was because that the Philistines were the Jewish "arch enemies" and others say it was because Palestine was the popular name of the land because of Herodotus.

Now Palestine as a nation, state, or a kingdom, did not exist prior to 1948 (and a few decades later)

The Palestinian nationality started to form rapidly with the establishment of the PLO in the 60's until the declaration of independence of Palestine in 1988 where they declared independence in a territory occupied by Israel after Jordan ceded it, which is why Israel considers it as disputed land and not Palestinian occupied land.

Hope I answered your question.