Citing Ancient Sources
With an ancient primary source, you cite author, work, book, and section in the footnote—for example, Tacitus Annals 3.76. The specific book or web transcription you used still goes in the bibliography as usual.
Why is it different?
The thing about ancient sources is, there are lots and lots of different versions, editions, and translations for each work. Think about The Iliad by Homer. There are hundreds of different versions, printings, and translations in English alone, not to mention every other language and printing that exists. Everyone has their own copy, and it could be any version of the original text. Referring to a page number in the edition you happen to have in front of you is of limited usefulness.
To get around this problem, scholars long ago divided each ancient work into books, chapters, and sections (for prose works) or books and line numbers (for poetry and plays). The other copies of The Iliad out there won’t have the page numbering you have—but they will be divided the same way.
You may already be familiar with this idea from a particular kind of ancient primary source—scripture. The Bible, Qur’an, Torah, and other scriptures are divided this way (e.g., John 3:16; Quran 2:185).
Examples
Here’s how it works in practice.
Only one work survives
“Every political system has a source of corruption growing within it, from which it is inseparable. For kingship it is tyranny, for aristocracy it is oligarchy, and for democracy it is government by brute force” (Polybius 6.10.3).
Polybius only survives via his greatest work, The Histories. Thus, no need to specify the work, just book, chapter, and section number.
Multiple works survive
“The busts of twenty most illustrious families were borne in the procession, with the names of Manlius, Quinctius, and others of equal rank. But Cassius and Brutus outshone them all, from the very fact that their likenesses were not to be seen” (Tacitus Annals 3.76).
Several works survive from the Roman historian Tacitus. For such writers, specify work, chapter, and section.
Poetry and plays
“No man or woman born, coward or brave, can shun his destiny” (Homer Iliad 6.489).
Homer’s works, Iliad and Odyssey, are epic poetry. They’re divided into books, then the lines are numbered within each book.
For ancient plays (not divided into acts as modern plays are), you give line numbers: e.g., Aristophanes Clouds 625-629.
Note: Print editions and better online transcriptions give chapters and sections—follow the links on the cites above for examples. Use the Ancient Texts page on my website to find online sources.