It requires a little effort to perceive that Shan Mû, the title of this Book, does not belong to it as a whole, but only to the first of its nine paragraphs. That speaks of a large tree which our author once saw on a mountain. The other paragraphs have nothing to do with mountain trees, large or small. As the last Book might be considered to be supplementary to 'the Nourishment of Life,' discussed in Book III, so this is taken as having the same relation to Book IV, which treats of 'Man in the World, associated with other men.' It shows by its various narratives, some of which are full of interest, how by a strict observance of the principles and lessons of the Tâo a man may preserve his life and be happy, may do the right thing and enjoy himself and obtain the approbation of others in the various circumstances in which he may be placed. The themes both of Books I and IV blend together in it. Paragraph 8 has more the character of an apologue than most of Kwang-dze's stories.