do what we are supposed to do". Since his views were impossible to disagree with, his forcefully expressed truisms enabled his installation as the central figure of Chinese poetic history. Moral engagement A second favourite epithet of Chinese critics is that of "poet sage" (, shī shèng), a counterpart to the philosophical sage, Confucius. One of the earliest surviving works, The Song of the Wagons (from around 750), gives voice to the sufferings of a conscript soldier in the imperial army and a clear-sighted consciousness of suffering. These concerns are continuously articulated in poems on the lives of both soldiers and civilians produced by Du Fu throughout his life. Although Du Fu's frequent references to his own difficulties can give the impression of an all-consuming solipsism, Hawkes argues that his "famous compassion in fact includes himself, viewed quite objectively and almost as an afterthought". He therefore "lends grandeur" to the wider picture by comparing it to "his own slightly comical triviality". Du Fu's compassion, for himself and for others, was part of his general broadening of the scope of poetry: he devoted many works to topics which had previously been considered unsuitable for poetic treatment. Zhang Jie wrote that for Du Fu, "everything in this world is poetry", Du wrote extensively on subjects such as domestic life, calligraphy, paintings, animals, and other poems. Technical excellence Du Fu's work is notable above all for its range. Chinese critics traditionally used the term (jídàchéng, "complete symphony"), a reference to Mencius' description of Confucius. Yuan Zhen was the first to note the breadth of Du Fu's achievement, writing in 813 that his predecessor "united in his work traits which previous men had displayed only singly". He mastered all the forms of Chinese poetry: Chou says that in every form he "either made outstanding advances or contributed outstanding examples". Furthermore, his poems use a wide range of registers, from the direct and colloquial to the allusive and self-consciously literary. This variety is manifested even within individual works: Owen identifies the, "rapid stylistic and thematic shifts" in poems which enable the poet to represent different facets of a situation, while Chou uses the term "juxtaposition" as the major analytical tool in her work. Du Fu is noted for having written more on poetics and painting than any other writer of his time. He wrote eighteen poems on painting alone, more than any other Tang poet.