This book presents an integral formulation of hydrodynamics in order to derive the pressure tensor and expressions of non-divergent transport coefficients. At the same time, the impossibility of finding pathologic solutions of the Liouville equation that may be identified with turbulence are examined. This book collects the ideas and papers that build up to the conclusion that turbulence is a quantum phenomenon, thereby encouraging more experimental and theoretical work in quantum non-equilibrium statistical mechanics. The book opens up a modern approach to the "classical" theory of turbulence, of interest to both engineers and physicists.