In his book "Color and Meaning - Art, Science and Symbolism", author John Gage speaks regarding the meaning attributed to colours: "As it happens, the only 'school' of colour-analysis in the history of art owes its development, not simply to the theoretical framework proposed in the nineteenth century by the Swiss critic Heinrich Wolfflin, who focused on the formal characteristics of visual style, including colour, but also, and more importantly, to the stimulus of the more recent philosophical tradition of phenomenology, represented in Germany chiefly by the philosopher Edmund Husserl. Lorenz Dittman's wide-ranging study, 'Farbgestaltung und Farbtheorie in der abendlandischen Malerei' ('Colour-structure and Colour-theory in Western Painting', 1987), is only the most important summation of a tradition of Koloritgeschichte (author's note: Colour history)."[7]