Matisse, Giacometti wrote: "Figures were never a compact mass but like a transparent construction". In the letter, Giacometti writes about how he looked back at the realist, classical busts of his youth with nostalgia, and tells the story of the existential crisis which precipitated the style he became known for. "[I rediscovered] the wish to make compositions with figures. For this I had to make (quickly I thought; in passing), one or two studies from nature, just enough to understand the construction of a head, of a whole figure, and in 1935 I took a model. This study should take, I thought, two weeks and then I could realize my compositions...I worked with the model all day from 1935 to 1940...Nothing was as I imagined. A head, became for me an object completely unknown and without dimensions." Since Giacometti achieved exquisite realism with facility when he was executing busts in his early adolescence, Giacometti's difficulty in re-approaching the figure as an adult is generally understood as a sign of existential struggle for meaning, rather than as a technical deficit. Giacometti was a key player in the Surrealist art movement, but his work resists easy categorization. Some describe it as formalist, others argue it is expressionist or otherwise having to do with what Deleuze calls "blocs of sensation" (as in Deleuze's analysis of Francis Bacon). Even after his excommunication from the Surrealist group, while the intention of his sculpting was usually imitation, the end products were an expression of his emotional response to the subject. He attempted to create renditions of his models the way he saw them, and the way he thought they ought to be seen. He once said that he was sculpting not the human figure but "the shadow that is cast". Scholar William Barrett in Irrational Man: A Study in Existential Philosophy (1962), argues that the attenuated forms of Giacometti's figures reflect the view of 20th century modernism and existentialism that modern life is increasingly empty and devoid of meaning. "All the sculptures of today, like those of the past, will end one day in pieces...So it is important to fashion one's work carefully in its smallest recess and charge every particle of matter with life." A 2011–2012 exhibition at the Pinacothèque de Paris focused on showing how Giacometti was inspired by Etruscan art. Walking Man and other human figures Giacometti is best known for the bronze