The Charles Francis Aiken Papers is a two series collection mostly composed of lecture notes spanning the late theology professor's 35 years at Catholic University. Series 1 focuses on his academic lectures and is perhaps of greater interest to scholars of theology, anthropology and religious history. Many of the notes in this series are handwritten, titled, and include bibliographic references. The lectures and marginalia from his stint at the University of Pennsylvania may be found in box 5. These suggest Aitken may have been a valuable intellectual contributor to that institution's Philosophy Department from 1897-1900 while he prepared his own master work comparing Jesus and Buddha.

As mentioned, Aiken was a published author and expert on apologetics. Though his published works are conspicuously absent from the collection, the scope of his lecture notes indicate a vast knowledge of world religions, the humanities, and the social sciences. (See boxes 2, 4 and 5.) Some evidence of this is revealed through assorted news-clippings pertaining to various anthropological and archeological discoveries from the early 20th century. In toto, the collection helps build the case that this robust era of emerging scientific theory and physical exploration had a profound impact on Aiken's thinking. In box 2 one may find extensive lecture notes titled "Early Man" and "The Origin of Species" blended with "Primitive Revelation." This suggests that Aitken was quite well versed in all manner of published work relating to the essence of humanity. Further, it is worth considering that much of Aiken's career coincided with the publication of sprawling ethnographic works such as Sir James George Frazer's "The Golden Bough." That work is particularly notable for it revealed a great deal of research on tribal and folkloric practices among polytheists, but drew controversy at the time due to Frazer's observations on Christianity.

Regardless "The Golden Bough" proved useful to Aiken through his notes in box 5 which reveal an articulate study of the origins of religion through lectures on Priests and Shamans and Sympathetic Magic. With the increasing popularity of anthropology and folkloric studies in more recent times, it is interesting to note the extent to which he researched non-Judeo-Christian belief systems. For example, cultural anthropologist E.B. Tylor is also frequently cited in the notes. That said, Aiken also felt compelled to assemble a comprehensive lecture on Mormonism, which is another rich resource in the collection. Looking back some 100 years, it is therefore tempting to view Charles Francis Aiken's broad curiosity about the world as a voice for human understanding at a time when the progress-minded colonial powers would soon find themselves descending into World War I.

Series 2 provides a more personal look at Aiken thanks to the inclusion of two personal diaries. Box 6 includes one box of sermons, possibly delivered in Boston, along with a personal diary from his seminary days. Finally, box 7 contains a travel diary from a cross-country journey in the spring of 1905 along with some papers from a Philadelphia area high-school.