Why is social life explicable, but unpredictable, or how does freedom give rise to determinism?

The article presents a critical reinterpretation and reconstruction of а key problem of social science: how a logically consistent and empirically substantiated explanation of social phenomena generated by the voluntarism of human actions, linked into complexes by a seemingly infinitely multiple contingency, is possible? In other words, we are talking about an attempt to answer the questions: how such a logically imaginary contingency is capable to generate elements of order at the empirical level, why social interactions have relative stability and reproducible character, what role do so-called unintended consequences of socially oriented (but dictated by «personal motives») human actions play in the processes of morphogenesis of society?