I very much appreciate all of your responses!
But alas the information I was looking for is not among any of them... I don't think my original post was clear enough; I apologize - I was in sort of a rush. I just spent the last 5+ hours digging through the search results of the following exact phrases on lawofone.info and still couldn't find the answer I'm looking for: "third density" "second density" "social complex" "purpose" "discover", and "origin". I'm seriously considering that what I'm looking for was in something I read elsewhere - one of Dolores Cannon's books, or Vol 1 of the L/L Research Channeling Archives, perhaps? Or maybe I'm misremembering, oy... I know for sure I read it somewhere though because the memory included the feeling of joy having been able to connect the dots for the first time as to why humanity is so obsessed with discovering the meaning of life and the universe/existence using all sorts of means and methods throughout history. Anyways I'm giving up for now; if it's there I'll find it when I do my upcoming deep-dive into each and every session.
I did find a couple related pieces of info that will better flesh-out my original post. This Q/A has to do with why humanity would likely be so concerned with their origin and meaning, being that we're a people from so many different planets, and therefore don't have a firm grasp on our origin/identity or what we're supposed to be doing with our lives:
91.13 Questioner: How many different planets have supplied the individuals that now inhabit this planet in this third density?
Ra: I am Ra. This is perceived by us to be unimportant information, but harmless. There are three major planetary influences upon your planetary sphere, besides those of your own second-density derivation, and thirteen minor planetary groups in addition to the above.
This is the Ra quote I was referring to in my original post:
60.16 Ra: We were, in fact, a more philosophical third-density planet than your own and our choices of polarity were much more centered about the, shall we say, understanding of sexual energy transfers and the appropriate relationships between self and other-self.
And then there's this, which I believe the "one orientation or seeking" Ra refers to is that of discovering our origin/meaning/etc., so as we're becoming a fully 4th density planet/people, more and more of us in the 3rd density are trying to answer the question of why we're here and what our purpose is:
11.17 Questioner: At what stage does a planet achieve social memory?
Ra: I am Ra. A mind/body/spirit social complex becomes a social memory complex when its entire group of entities are of one orientation or seeking. The group memory lost to the individuals in the roots of the tree of mind then become[s] known to the social complex, thus creating a social memory complex. The advantages of this complex are the relative lack of distortion in understanding the social beingness and the relative lack of distortion in pursuing the direction of seeking, for all understanding/distortions are available to the entities of the society.
There's a chance I'm reading into some of this wrong; if you've got them, feel free to offer your opinions, criticisms, corrections, etc.!