 The general and prolific poet Lu Ji used Neo-Taoist cosmology to take literary theory in a new direction with his "Wen fu", or "Essay on Literature" in the "fu" poetic form.The Jin dynasty was divided into an "eastern" and a "western" phase.Really, though, this may be less helpful of a description than saying that in terms of general geography the most apparent geographic difference between the first part and the second part of the Jin dynasty was the loss to the empire of the northern parts above the Huai River.