One idea propounded by Hayek is central for the understanding of the Social Sciences: the notion of complex phenomena. This notion was originally introduced in his paper “The theory of the complex phenomena” published in Studies in 1967.
In that paper, Hayek propounds that the degree of complexity of a phenomenon depends upon “the minimum number of elements of which an instance of the pattern must consist in order to exhibit all the characteristic attributes of the class of pattern in question…” In this sense, almost all the phenomena studied by the Social Sciences are complex phenomena, since the number of interdependent variables that should be represented in their models is so large that only some of them could be observed and studied. Moreover, it would be impossible to test all the combination of elements and then, to make predictions with complete information. In conclusion, the only kind of predictions that we would be able to produce in Social Sciences is pattern predictions, that is, predictions about when or under which circumstances certain kind of regularity could emerge.
In relation to this, it is interesting to see the relation proposed by Hayek between the notions of “order” and that of “complex phenomena”. In fact, he states in the first paragraphs of the chapter on “Cosmos and Taxis” (Law, Legislation and Liberty, Vol. 1, Chap. 2, p.35): “Order is an indispensable concept for the discussion of all complex phenomena, in which it must largely play the role the concept of law plays in the analysis of simpler phenomena” And then he introduces a footnote with the citation of his own paper on complex phenomena. Can this be understood as if he is subsuming the study of the spontaneous orders to the study of the complex phenomena? I will return on this point later, but meanwhile I am looking forward to your comments!