Research Advice for Ancient Philosophy

Use reference resources

Reference resources are things like encyclopedia articles, chapters in handbook or companion volumes, or articles in journals that focus on literature reviews, such as Philosophy Compass. Their purpose is to provide you with an overview of a topic and to discuss relevant research.

Reference resources can save you a lot of time and effort. You can use them to check your understanding of a given philosopher or topic, and/or a guide to further reading. The bibliography or works cited list at the end of a good reference resource will gather together books and articles that the author believes are important to the state of research on the topic.

This page on the Philosophy Subject Guide provides links to a number of reference resources.

You can also find reference resources by search on the library’s website. Select Articles and More from the dropdown menu, and search for your topic. Then, on the right-hand side of the results page, limit your search to Reference.

If you have a reference for a journal article…

Use Falvey’s Journal and Article Finder any time you have a reference for a journal article that you want to find (from your course readings, from a reference resource, or from another journal article).

You’ll have to start by searching for the journal’s name. In the search results you’ll find a link to one of several access points to that journal, and you can then navigate to the specific issue you’re looking for.

The Journal and Article finder can be found on the library’s homepage, or at this link.

Use Philosophy databases for very specific topics

Journal articles in philosophy tend to be highly specialized, and can be difficult to search for. But if you wan to find detailed discussions of, say the notion of flux in Heraclitus, or the role of external goods in Aristotle’s Nicomachean Ethics, they can be very useful.

The two best databases for philosophy are Philosopher’s Index and PhilPapers. I recommend the former, since it allows you more control over how you search.

If you don’t find relevant articles at first, try to think of synonyms for some of the keywords you’re using.

The subject limiter on the left-hand side of the search results page is also very useful. It will show you the subject headings for all of the results of your search. You can use them to further limit the results, or you can try using them in combination with other keywords.

Citing sources in Chicago Style

Falvey has a page outlining the main components of Chicago Style citations here.

You can also find the complete edition of the Chicago Manual of Style here. I recommend using the Citation Quick Guide for examples of how to cite the most common types of materials.


How to cite ancient texts

Citations to ancient sources frequently refer to a specific, standard edition of the text in question, which serves as the basis for various modern editions and translations. Numbers of pages, lines, or sections of the standard edition are printed in the margins of the modern edition so that users of different editions and translations can refer to a specific passage in the text and know that their readers will be able to find it, even if they are using different translation.


Citations to Plato use Stephanus numbers, which come from a comprehensive edition of his works produced during the Renaissance. Stephanus numbers can be found in the margins of most editions and provide both the page number and the page section (a through e) of the Stephanus edition.

To cite a passage you will need to give both the Stephanus page and page section on which the passage appears.

Plato, Apology, 35d.

Since passages may take up more than one Stephanus page or page section, you will often need to indicate a range. The following citation is for a passage from the Sophist beginning in section b of page 227 and continuing through section c of the same page:

Plato, Sophist, 227b-c.

Here is how you would cite a passage from the Phaedo beginning at page 85, section e, and ending at page 86, section d:

Plato, Phaedo, 85e-86d.


The margins of most editions of Aristotle contain Bekker numbers, which refer to a standard edition prepared by Immanuel Bekker in 1831. Bekker’s edition presented two columns of text on each page, column a and column b. As a result, Bekker numbers provide three pieces of information: the page in Bekker’s edition, the column on that page, and the line of text in that column.

Page and column always appear together, so as we scan through the text we will see page/column 1103a appear before page/column 1103b.

To cite lines 15 through 18 on page 1103, column a, of Aristotle’s Nicomachean Ethics, one would write:

Aristotle, Nicomachean Ethics, 1103a15-18.

To cite a passage beginning on one column of a page and ending in the next column of the same page, indicate the range like this:

Aristotle, Nicomachean Ethics, 1105a17-b19.

Because English translations take up a different amount of space than the Greek original, Bekker numbers in English editions of Aristotle are slightly imprecise.

It is also conventional to divide individual works by Aristotle into books and chapters. Books are frequently numbered in Roman numerals, and chapters in Arabic ones, although this is not always the case. Book II, Chapter 4 of the Nicomachean Ethics can be abbreviated as II.4, or as 2.2.

The Presocratics

One common way to cite the presocratics is to refer to how they appear in Hermann Diels’ compendium Die Fragmente der Vorsokratiker. Later editions of Diels were overseen by Walther Kranz, and so the work is usually abbreviated as DK.

DK collects material concerning 90 different presocratic writers, in numbered order. The sections for each writer are further divided into A and B categories: A for the testimonia, and B for the fragments.

A reference to a given testimony or fragment thus contains four elements: “DK” to indicate that we’re referring to Diels, the number for the specific writer, the letter A or B indicating which category of text we’re referring to, and the number of that text.

For example, if we want to refer to fragment 3 by writer 11 (Thales), we write:

DK 11 B 3.

Note that this reference leads the reader directly to the Greek text as it appears in Diels. If you are working from an English translation, be sure to indicate which one. Include a full reference to the translation in your bibliography. Page references to the translation can be provided in footnotes as well, alongside the DK reference.