important questions. Any adequate treatment of such issues is outside the scope of this
work, but we have provided a Glossary of commonly used terms, giving a brief discussion
of their meaning, with some references. Entries refer to these terms in bold, or for terms
transliterated rather than translated, in bold italic.
Three indices or appendices, to aid consultation and cross-referencing, are provided:
(1) topical or categorical index, listing all authors astronomical, geographical, medical, etc.,
in order to facilitate understanding the degree to which ancient science was understood by
its practitioners as straddling multiple traditions; (2) the “Time-Line,” a chronological
index, to facilitate understanding the chronological development of ancient natural science;
(3) the “Gazetteer,” a geographical index, listing by place of author’s origin all entries for
which that is possible, to clarify the diverse origins of the scientists and the degree to which
ancient science was conducted away from the two traditional intellectual centers of Athens
and Alexandria.
The Gazetteer shows that scientists originated from a wide variety of locales: over 325 are
listed for the almost 1,000 scientists (i.e., about half those in this encyclopedia) whose place
of origin is attested or inferred (thus, an average of three scientists per locale). Alexandria
(with ca 80) and Athens (with ca 50) indeed each produced more scientists than any other
two places together; but 16 other sites also produced significant numbers (at least thrice the
average): Samos (22), Kure ̄ne ̄ and Mile ̄tos (at least 17 each), Rhodes (16), Ephesos, Ko ̄s,
and Surakousai (at least 13 each), Pergamon, Smurna and Tarsos (at least 11 each), plus
Buzantion, Khios, Knidos, Kuzikos, Taras, and Tralleis (at least ten each). The total for
Alexandria or Athens, although many times the average, amounts to only 1/8 of the num-
ber of scientists whose place of origin is known (8% for Alexandria; 5% for Athens). Those
two centers did produce (and attract) many scientists, as indeed one would expect for places
that provided resources and an environment congenial to the practice of science. But pros-
perity, trade, and democracy seem also to promote the practice of science, or at least be
correlated with it, as can be seen in the list of 16 cities above, which altogether provided at
least 204 (ca 1/5) of the scientists whose place of origin is known. (That conclusion is based
upon only half of our entries, but to alter it significantly would require establishing a place
of origin for a large number of the unassigned scientists, which itself would be a welcome
result.) The same can also be seen in the Gazetteer as a whole: scientists come primarily
from prosperous places open to outside influences and which foster free discussion of ideas
(cf. Keyser in Irby-Massie and Keyser 2002, c. 1).
The Time-Line shows that the practice of science was not uniform over time, as may
well be expected; but the “classical” era of Hippokrate ̄s, Plato, and Aristotle was not the
most productive – rather the 4th to 3rd cc. and the 1st c. through 1st c. were
(the “dip” in the 2nd c. may be an artifact of fragmentary data). Periodization is
always a scholarly imposition of discontinuity upon complex and continuous data, since
every era is transitional between its own past and its own future. Nonetheless, using only
those scientists who are relatively narrowly dated (about half those in this encyclopedia),
we create Fig. 1 of the Time-Line, showing the rapid rise in the 5th c. and rapid
decline after Hadrian. As previously argued (ibid.), the decline seems due to the centraliza-
tion of political power under Hadrian and abolition of semi-autonomous polities through-
out the Mediterranean world, with the consequent loss of a context within which science
could flourish. No doubt these conclusions should be held somewhat tentatively, given the
likelihood that many names have been entirely lost, especially in the latest periods (and
perhaps also in the turbulent and less-well-known periods of the 2nd c. and 3rd c. ).
INTRODUCTION