When and why do scholars become revolutionaries? This question has been occupying my mind for some time, in its most general form. But, though I would like to discuss it in this general way, it seems more manageable-and quite ambitious enough-for the purpose of this paper to consider it in the context of two specific regions which I know something about, Vietnam and West Africa, more particularly the Western Sudan, and to try to make some comparisons between them. At the outset one is struck by certain points of resemblance between the two systems. Both Vietnamese and West Sudanic societies have been much influenced-as regards their poetry and cookery as well as their administration and their law-by adjacent civilizations, the Chinese and the Arab; and by world-views which have emerged within those civilizations-Confucianism and Islam-each associated with a specific script, an extensive literature of 'classics' composed in the script, and a class of scholars trained in the use of the script and the ability to read, understand, comment on, pass on knowledge of, the 'classics'. In both Vietnam and West Africa these various constituents of the adjacent civilizations-world-view, script, 'classics', scholarly class-have influenced the local societies for more than a millennium (in Vietnam much more). In both, side by side with 'classical' literature (in Chinese and Arabic), there developed an indigenous literature, particularly poetry, written in Vietnamese on the one hand, in Kanuri, Fulfulde, Hausa, Malinke, etc, on the other, in modified forms of Chinese and Arabic script. In both societies, coincidentally or otherwise, there were important transformations in the fifteenth century and late-eighteenth/early-nineteenth century. In Vietnam, after the defeat of the Ming invasion and occupation in 1427, under Le Loi-leader of the liberation movement and founder of the Le dynasty which survived for the next 360 years-and Le Thanh Tong (I460-I497), reformer, centralizer, expansionist, patron of learning, poet, there was an important shift in the balance of power within the state towards the Confucian-trained bureaucracy, the mandarinate. This was associated with a strengthening of the examination system (the ceremony of proclamation at the palace of the names of candidates who had been successful in the national examinations was introduced in 1462; their names began to be inscribed on the stelae at Van Mieu, the Temple of Literature, in Hanoi in I484) and a growth of the production of learned works, particularly encyclopaedias. One can compare what was happening in some of the Muslim states of the Western Sudan (Bornu, Kano, Katsina, Songhai) at roughly the same period -bureaucratization, political expansion, growth of a scholar class, development of centres of learning, production of Arabic works. Comparison between the late-eighteenth/early-nineteenth transformations in the two societies is more complicated. In both revolutions occurred, more significant in character