the skin and produce hair-growth. Wellmann tentatively equates him with the oculist “C.
Iulius Dionysodorus” known from a collyrium stamp: Grotefend (1867) #43; but the
name is exceedingly common (LGPN).
RE 5.1 (1903) 1004–1005 (#17), M. Wellmann.
PTK
Dionusodo ̄ros, Maecius Seuerus (100 – 200 CE)
Platonist, wrote a commentary on the Timaeus, to which P repeatedly refers (e.g. in
Tim. 1.204.16–18), and On the Soul (possibly part of the same commentary), from which
E (PE 13.17) preserves an extract. “Seuerus,” as he is known in the later tradition, is
probably identical with “Flauius Maecius Se[.. .] Dionusodo ̄rus, Platonic philosopher
and counselor” honored in an inscription from Antinoe ̄, IBM IV 1076 = SB III 6012. A
Dionusodo ̄rus mentioned by D L (2.42) may well be the same person.
Seuerus was read in P’ school. S (in Metaph. 84.23–5) censures Seuerus for
misusing mathematics to study nature.
Ed.: Gioè (2002) 379–433.
RE 2A.2 (1923) 2007–2010, K. Praechter; P. Cauderlier and K.A. Worp, “SB III 6012 = IBM IV 1076:
Unrecognised Evidence for a Mysterious Philosopher,” Aegyptus 62 (1982) 72–79; Dillon (1996)
262 – 264; NP 11.484–485, M. Baltes and M.L. Lakmann.
Jan Opsomer
Dionusodo ̄ros (of Kaunos?) (ca 200 BCE)
We know of three geometers named Dionusodo ̄ros: (1) of Amise ̄ne ̄, mentioned by
S (12.3.16), (2) of Me ̄los, mentioned by Strabo ̄n (ibid.) and P (2.248), who
relates a foolish anecdote about his funeral inscription, and (3) of Kaunos, one of
the teachers of P, and thus a member of a circle of intellectuals including
the mathematicians A P, Eude ̄mos of Pergamon (otherwise unknown),
Z, and probably D. This milieu makes Dionusodo ̄ros of Kaunos
the most credible candidate for the authorship of two sophisticated geometrical results
attributed to an unspecified Dionusodo ̄ros.
E (In Arch. Sph. Cyl. pp.152–160 H.) quotes an alternative solution by Dionuso-
do ̄ros to the problem of dividing a sphere by a plane such that the two segments are in a
given ratio, which A reduced to a complex division of a line segment in Sphere
and Cylinder 2.4. Dionusodo ̄ros’ construction solves the problem by finding the intersections
of a parabola and a hyperbola. H (Metrika 2.13) reports that Dionusodo ̄ros’ On the
To r u s contained a formula effectively relating the volume of a torus to the diameters of the
generating circle and the circle of revolution. The proof, which probably resembled
Archime ̄de ̄s’ procedures in Sphere and Cylinder and other works, is lost. V (9.8)
attributes the invention of the conical sundial to a Dionusodo ̄ros.
DSB 4.108–110, I. Bulmer-Thomas; Knorr (1986) 263–277; R. Netz, The Transformation of Mathematics
in the Early Mediterranean World (2004) 29–38.
Alexander Jones
DIONUSODO ̄ROS, MAECIUS SEUERUS