TITLE: Searching for an early, highly theoretical, even philosophical, math paper on models or small-world networks
QUESTION [6 upvotes]: All I can remember is that it was very high-level / abstact and kind of philosophical, explaining (the discovery or interdependence of) small world networks. I assume that it was +50 years old and 'might' be an iconic paper, but maybe not - surely it was by far not as popular as the, already mentioned, paper "small world networks and their dynamics" by Duncan J. Watts & Steven H. Strogatz, but also it was on a completely different level of math.
I think I found it once on Azimuth Blog from John Carlos Baez. But it is very large and I don't even find "small world network" in the search (it might have also been mentioned by someone in the comment section).

REPLY [4 votes]: I am answering my own question, because I actually did find it again (after 5 years and many tries).
It was not even close to being iconic nor +50y (it just looked old) nor specific on small networks :)

Rosen, R. (1993). On models and modeling. Applied mathematics and computation, 56(2-3), 359-372. PDF

Thanks @Carlo Beenakker for bringing up the Milgram paper!