Political analogies abound in Roman discussions of natural philosophy, arguably the most
famous of which are found in the De Rerum Natura of Lucretius, which portrays atomic
compounds forming assemblies (concilia, coetus) and compacts (foedera) in the manner of
Republican Roman citizens. Numerous scholars since Fowler (1989) have noted the
‘republicanism’ of Lucretius’s social metaphors, and the poet’s frequent conflation of political
and philosophical terminology unites his philosophical agenda with his call for an end to
contemporary civil strife (Gladhill 2016; Hammer 2014; Schiesaro 2007). However, while
scholarship on political metaphor in first-century Roman philosophy has focused largely on De
Rerum Natura, Cicero’s philosophical writings offer a valuable—and understudied—point of
comparison from an anti-atomist perspective. In particular, the various accounts of Epicurean
atomism in Ciceronian dialogues from the mid 40s BCE reveal a set of tendentious political
metaphors in opposition to those of Lucretius. In this paper I examine the use of political
discourse in Cicero’s descriptions of Epicurean atomism, arguing that the Roman statesman
likens non-teleological atomism to the violent disruptions of mob rule and populist demagoguery
in the late Republic.
In two different dialogues, Cicero compares atoms to the urban mob at Rome, referring to
the “crowd of atoms” (atomorum turba; Tusc. 1.11.22) and their “turbulent collision” (turbulenta
concursio; Fin. 1.6.20). Hellegouarc’h (1963), citing widely from late Republican and Augustan
literature, argues that both turba and turbulentus possess strong connotations of mob violence
and populist political disorder—a persistent feature of public politics in the final decades of the
Republic—and it follows that this would have been keenly felt during the period of 45-44 BCE.
Even for Lucretius, a bona fide atomist writing in the 50s, the metaphor of the atomic turba applies specifically to disordered groups of atoms, which he contrasts with the positive political
metaphor of a coetus (‘gathering’) or concilium (‘assembly’) when those atoms successfully
combine to form a larger, ordered whole (Cabisius 1984-5). Cicero’s turba atomorum, therefore,
is not just a crowd by virtue of its numbers, but by its lack of effective guidance and its supposed
propensity to disorder and violent collision.
A related example occurs in De Natura Deorum, when one of the interlocutors
supplements his formal arguments regarding chance and regularity by characterizing the motion
of atoms as not just impossibly random, but reckless: concurrentibus temere (“colliding
recklessly”, Nat. D. 2.37.94; cf. Nat. D. 2.44.115). In his study of political language in the late
Republic, Weische (1966) argues that temeritas (“recklessness”), along with temere and
temerarius in post-Sullan political discourse, is closely associated with the rashness of mobs and
demagogues at Rome, which Cicero in his political speeches repeatedly contrasts with the
prudent judgment of the senatorial aristocracy (e.g. Cic. Flac. 58).
Lastly, I discuss a provocative line from De Natura Deorum in which one of the
interlocutors castigates Epicureans for reducing all of cosmology to the “tyranny and
licentiousness of atoms” (abuteris ad omnia atomorum regno et licentia, Cic. Nat. D. 1.23.65).
In a strictly philosophical sense, the metaphor of political tyranny (regnum) ridicules the absolute
authority given to atoms in Epicurus’ reductionist explanations of natural phenomena, while the
atoms’ licentiousness (licentia) ties the behavior of atoms to odious developments in
contemporary politics, analyzed in detail at De Re Publica 1.67-8 (Reinhardt 2005).
I conclude by considering how Cicero’s political characterization of atoms fits into the
broader cultural landscape of the mid 40s. As Baraz (2012) has demonstrated, Cicero’s later
dialogues are intimately connected with his political ambitions under the new Caesarian regime, and the same can be said for his treatment of atomic physics. When Cicero applies negative
political catchwords and metaphors to atomism, it has the effect of equating Epicurean physics
with the sort of mob violence, demagoguery, and eventual tyranny that ended republican
government at Rome and forced Cicero himself out of politics and into philosophical writing.