[A rarity for me, I took no notes nor marked any significant passages when I read this book. This is mainly because I'd like to buy a copy in the original German and read it again more closely.]
Part I: Meaning is essentially an order, comprised by either purpose or form.
Part II: History is not merely past events (á la historism) nor the record of them (á la historicism), but the interaction of these two dimensions of human experience. History as such emerged from the Greek-Asian obsession with flux and cyclical world-patterns by way of the Jewish sense of a messianic eschaton, which was, in turn, made radically "worldly" by the Christian Incarnation, which, in turn, ultimately led to a progressive secularization of the world by positing a purely spiritual eschaton, thus leaving "the world" to run on its own, as it were.
Part III: Since there is no discernible cosmic purpose, but there is a definite historical form, the proper "purpose" of history is for humans themselves to preserve and enrich the human form in history.