I had a question about the Masoretic divisions in the Tanach, specifically the "פ" and "ס" notations.
I know that the division into chapters was a Christian development that has been accepted for convenience in Jewish editions of the Bible. I'm guessing the Christians editors tried to separate between chapters on somewhat of a thematic basis, which is not always in agreement with a the Rabbinic interpretation.
My question is how do the "פ" and "ס" notations relate to theme? Does every break denote an entirely new parsha, with the content of one separate from the other? In nevi'im, do separate parshiyot indicate different nevuot that took place at different times?
For example, in Yeshayahu 43, pasuk 9 says:
כָּֽל־הַגּוֹיִ֞ם נִקְבְּצ֣וּ יַחְדָּ֗ו וְיֵאָֽסְפוּ֙ לְאֻמִּ֔ים מִ֤י בָהֶם֙ יַגִּ֣יד זֹ֔את וְרִֽאשֹׁנ֖וֹת יַשְׁמִיעֻ֑נוּ יִתְּנ֤וּ עֵֽדֵיהֶם֙ וְיִצְדָּ֔קוּ וְיִשְׁמְע֖וּ וְיֹאמְר֥וּ אֱמֶֽת׃
Were all the nations gathered together, and kingdoms assembled, who of them would tell this or let us know of the first events? Let them present their witnesses, and they shall be deemed just, and let them hear and say, "True."
Whereas later on in pasuk 18:
אַֽל־תִּזְכְּר֖וּ רִֽאשֹׁנ֑וֹת וְקַדְמֹנִיּ֖וֹת אַל־תִּתְבֹּנָֽנוּ׃
Remember not the first events, and do not meditate over early ones.
These are in two separate parshiyot. What is their relationship? Are they meant to be read in context of each other, or separately?