To the mathematicians, correlation is a statement about random variables, and not the same as empirical correlation (which is a statement about samples, and might be spurious).
Of course the world isn't made of random variables, but only in the same sense that the world isn't made of causal models. They are models, and "correlation" and "causation" are features of the model which don't exist in the real world. In a causal model, correlation implies causation (somewhere).
Emphasizing random variables sounds pretty frequentist to me, while the source being summarized is bayesian. But, yes, models are made of random variables.
People want to tell everything instead of telling the best 15 words. They want to learn everything instead of the best 15 words. In this thread, instead post the best 15-words from a book you've read recently (or anything else). It has to stand on its own. It's not a summary, the whole value needs to be contained in those words.
I'll start in the comments below.
(Voted by the Schelling study group as the best exercise of the meeting.)