This dissertation seeks to contribute to a rethinking of the intellectual history of nineteenth century West and North Africa through examining the writings of James Africanus Beale Horton and Rifa'a al-Tahtawi. My focus is on the history of philosophy and science, and the possibility of situating Horton and Tahtawi in the context of the global history of modern philosophy and science. The aim is to show that African intellectuals participated in some of the key debates that characterized and shaped modernity, and that their engagement in these debates cannot be explained away as being merely the result of their “mental colonization”. I argue that far from being mentally colonized, both Tahtawi and Horton had good reasons for holding the views that they held, e.g., the universal validity of modern scientific knowledge, and the possibility of a truly universal philosophy of history centered on the belief in progress. I have chosen to compare a figure from North Africa with a figure from West Africa precisely because the idea that the Sahara desert has been a barrier between Africa south of the Sahara and North Africa has led intellectual historians of Africa and historians of African philosophy to overlook the similarities between the intellectual ferment which took place in parts of West Africa (especially in Sierra Leone, Liberia, Lagos, and the Gold Coast) during Horton’s life time (1835 – 1883), and the intellectual ferment which took place in Tahtawi’s Egypt over the course of his lifetime (1801 – 1873). Both Horton and Tahtawi, subscribed to philosophies of history centered around progress, and they both believed that modern European societies were superior to their own societies in certain ways (specifically with respect to the social organization of knowledge production), but they differed from many nineteenth century European intellectuals insofar as they did not take these facts as justifying European despotic rule over non-Europeans in general or any form of biological racism.