Thomas Jefferson: Reflections on the Enlightenment

When we reflect back on Jefferson’s life, we tend to focus on his association with the American Revolution, particularly as principal author of the Declaration of Independence. We may consider his monumental role in opening up the West (e.g. The Louisiana Purchase), as well as his time spent in various positions in government, including as two-term president of the United States.  What we may under appreciate, however, are the influences the 18th century Enlightenment had on his beliefs, actions, and even his character.

In the “dining room” of Thomas Jefferson’s retreat home of Poplar Forest, located in Forest, Virginia, there are features that seem to track nicely with the Enlightenment.  In that room, Thomas Jefferson commissioned artisan William Coffee to construct an entablature[i] resembling the one found in the ruins of the Baths of Diocletian in Rome, the latter a Roman emperor of the late 2nd and early 3rd centuries A.D.  Like Diocletian’s entablature, Jefferson’s version included images of the “face” of the mythical Roman god, Apollo, although the Jefferson entablature also included ox skulls, something not part of the original Diocletian entablature.  More on that later. 


There is no known record as to why Jefferson decided to re-create the entablature of Diocletian, to include its bearing the likeness of Apollo.   However, during the Enlightenment, the image of Apollo was often used as a kind of metaphor representing illumination, especially the illumination of the mind through acquired knowledge and reason.

Even the great skylight, seen in the dining room at Poplar Forest, hints at a connection both to antiquity and to the Enlightenment. For example, the skylight is set in an east-west orientation, directly above a centrally positioned likeness of Apollo. In Greco-Roman mythology, Apollo moved the sun across the heavens in an east-west direction. Such a metaphoric representation may have been on Jefferson’s mind with his design, in addition to perhaps a more mundane interest of optimizing sunlight for practical purposes.  Thus, the dining hall is illuminated by light, while the mind is illuminated by the “light of reason.”

As Enlightenment scholar, Professor Dorinda Outram emphasized, “Enlightened people moved as a matter of course among words and images of radiance, of sunlight, illumination, and clarity.”[ii]  So did Thomas Jefferson.  

This brings us to the ox skulls and to Diocletian.  How might these relate to Jefferson and the Enlightenment?  Foremost, we do not know for certain if there is a connection.  However, in Roman times, ox skulls were symbolic of sacrifice. Perhaps Jefferson’s insistent addition of ox skulls was also intended as a metaphor, something pointing to self-sacrifice in service to the nation and liberty.  Finally, what about Diocletian?  The answer may lie in who was Diocletian.  Diocletian became emperor following a very tumultuous period in Roman history, referred to by historians as the Crisis of the Third Century.  Diocletian stabilized the empire by reorganizing the administration, restructuring the military, and advancing economic reforms such as lowering taxes.  Then he did something unheard of for almost any time in human history, much less during the period of the Roman Empire. Diocletian abdicated the throne voluntarily—walking away from Imperial power.  In a sense, on 4 March 1809, that is precisely what Thomas Jefferson did in following the peaceful transition of power previously institutionalized by both the Washington and Adams administrations.    

Upon further reflection, I wonder if President Jefferson’s entire Poplar Forest retreat was meant to be a kind of metaphoric grand temple of inexorably linked light and liberty: 

“…this ball of liberty, I believe most piously. Is now so well in motion that it will roll round the globe, at least the enlightened part of it, for light and liberty go together.” –Thomas Jefferson (1 June 1795)

Dave Dietrich


Dave Dietrich served for over forty years as a professional national security analyst and educator at the international (NATO), national, and military service levels.  Since his retirement in 2015, he has been working both as an Assistant Professor of Political Science (adjunct) and as a volunteer docent at a Thomas Jefferson historical site.  Mr. Dietrich is also an occasional guest instructor at the School of Education of Johns Hopkins University (History of Intelligence).  He holds a Master of Science degree in Strategic Intelligence.  

[i] Photo Source, Thomas Jefferson’s Poplar Forest, with permission
[ii] Dorinda Outram, The Enlightenment; (New York: Cambridge University Press, 3d edition 2013); ISBN-978-1-107-02739-8, p. 37