Mathematici

Definition

Mathematici is the Latin plural designation under which astrologers appeared as a legal class in Roman law. The term originally meant 'mathematicians' but was used in imperial Roman legislation specifically for practitioners of astrology, often grouped with other divinatory practitioners (Chaldaei, arioli) targeted by edicts from Augustus onward. The class designation persisted in Roman legal vocabulary into the Late Antique period.

In Tradition

Across the Greco-Roman tradition the mathematici occupied a contested legal and intellectual position: high-status practitioners consulted by emperors and senators on one side, criminalised diviners liable to capital punishment when consulting on imperial-fate matters on the other. The legal record preserves Ulpian's careful distinction between knowledge of the art (permitted) and the practice of it for clients (forbidden), a distinction that shaped how the astrological-technical literature circulated even when active practice was outlawed.

In Practice

Reading any Greco-Roman astrological text — Ptolemy, Vettius Valens, Pseudo-Manetho, Hephaestion — requires the historical awareness that its authors and practitioners operated as mathematici under a legal regime that intermittently criminalised them. The Augustan edict of AD 11 banned predictions to individuals singly and predictions about death; five years later, senatus consulta deprived mathematici of fire and water with property confiscation, with foreigners put to death. Yet Cramer documents that the theoretical literature on horoscopic life-prediction continued to be treated in astrological manuals for centuries after the principate — 'writings on the subject seem to have circulated freely.' Modern Hellenistic-revival practitioners encounter the term in scholarship on the social-legal context of the surviving doctrinal corpus.

Historical Origin

The legal history of the mathematici is documented by Lightfoot citing Cramer's *Astrology in Roman Law and Politics*, Dio Cassius 56.25.5 (preserving the gist of Augustus' AD 11 edict), and Ulpian's *De Officio Proconsulis* 7 (preserved in *Mosaicarum et Romanarum Legum Collatio* 15.2.2). The Justinian Code IX.18.5,7 and Theodosian Code IX.16 continue the legislative tradition into Late Antiquity, eventually superseded by a total ban on divination in the 4th century.

Etymology

Origin: Latin. Meaning: From mathematicus (sg.), mathematici (pl.), 'mathematician' — Latin loanword from Greek μαθηματικός (mathēmatikos, 'mathematical, one skilled in the mathēmata or learned arts'). In imperial Roman legal usage the term shifted to designate astrologers specifically..

Further Reading

• J. L. Lightfoot, The Apotelesmatika of Manetho
• Claudius Ptolemy, Tetrabiblos
• Vettius Valens, Anthologiae