One of the most delicate aspects of writing a thesis is adopting a coherent and clear system of bibliographic references in the text. This short guide is intended to assist students who are writing a thesis under my supervision through this process. For the structure of the thesis and the use of notes, see the guide on how to write a research article. Here, instead, you will find the rules to follow for bibliographic references in the text and in the final bibliography.

The main feature of this system is the distinction between (1) secondary literature, (2) primary sources, and (3) manuscripts. Secondary literature follows the standard author-date system, whereas ancient and medieval sources are cited through the author, the title of the work, and its internal reference system. Manuscripts are identified through place, library, shelfmark, and folio.

This guide is divided into three main sections, which explain:

• the system of bibliographic references,
• the final bibliography,
• the main formal rules to follow in the thesis.

THE SYSTEM OF BIBLIOGRAPHIC REFERENCES

The system adopted here distinguishes three types of material, which must be treated differently:

1. secondary literature, which is cited using the author-date system;
2. premodern primary sources, which are cited through the author, the title of the work and, whenever possible, the internal divisions of the text;
3. manuscripts, which are identified through place, library, shelfmark, and folio.

This distinction is fundamental: a monograph published in 2014 and a work composed in the thirteenth century are different bibliographic objects. For this reason, medieval sources follow their own system.

The author-date system

In the author-date system, the bibliographic reference is inserted directly into the main text, in parentheses. The reference contains the author’s surname, the year of publication and, when a specific passage is cited, the page or page range. For example: (Brower 2014, 109–184). Note that:

• If the author’s name already appears in the sentence, only the year and any relevant pages are given in parentheses. For example: “Brower (2014, 109–184) argues that…”
• When referring to a work as a whole, page numbers may be omitted. Example: (Hasse 2000).
• Several references may be included in the same parentheses and separated by semicolons. Example: (Brower 2014; Petagine 2019; Friedman 2021).

Full bibliographic information is provided in the final bibliography. For example, the reference (Brower 2014, 109–184) corresponds to the following complete bibliographic entry:

• Brower, Jeffrey E. 2014. Aquinas’s Ontology of the Material World: Change, Hylomorphism, and Material Objects. Oxford: Oxford University Press.

The main advantage of this system is that it keeps references short and makes the date of the cited literature immediately visible. In our case, however, the system is applied to secondary literature. Ancient and medieval primary sources follow the specific rules explained in the sections below.

Forms not to use

In the author-date system, forms such as ibid., ibidem, id., ead., idem, eadem, op. cit., loc. cit. or similar expressions are not used. The author-date reference must be repeated even when it refers to the same work cited immediately before.

For example, a reference such as (Brower 2014, 120) may be followed by (Brower 2014, 124). This solution makes each reference self-contained and reduces the risk of ambiguity during revisions of the thesis.

Premodern primary sources

Primary sources constitute the most important exception to the author-date system. When a work has a stable system of internal divisions, the reference must make it possible to identify the passage independently of the modern edition used. For example:

• (Aristotle, Metaphysics Z.10, 1036a8)
• (Oresme, Quaestiones super Physicam I.14, 104)
• (Thomas Aquinas, In Phys. I, 118 [9], 59)

Abbreviated titles may be used for works cited frequently, provided that they are conventional or clearly explained. For example:

• ST = Summa theologiae
• In Phys. = In octo libros Physicorum Aristotelis expositio
• De ente = De ente et essentia

The aim is to allow the reader to locate the passage even when using a different edition. Particular care must be taken with certain kinds of primary texts, especially scholastic works. Their internal divisions may be considerably stratified into books, distinctions, questions, articles, and so on. For example: (Duns Scotus, Lectura II, d. 3, q. 1, n. 24).

Critical editions

A modern critical edition of a medieval work must appear in the bibliography, but the year of the edition does not become the reference system for the work, unlike what happens with secondary literature. If a work does not have sufficiently precise internal divisions, the page number of the edition used may be added.

For example, if a modern edition of the Lectura of Duns Scotus is used, the text should cite (Duns Scotus, Lectura II, d. 3, q. 1, n. 24) rather than (Duns Scotus 1993, 24). The bibliography will then allow the reader to identify which edition of the Lectura was actually used.

Translations of primary sources

When a primary source is consulted or cited through a modern translation, the reference must continue to identify first of all the author and the passage of the primary work. The translator’s name and the year of the translation must be added as additional information. For example:

• (Thomas Aquinas, De ente, chap. 2; trans. Porro 2002)

In this way, the canonical reference identifies the passage of the work independently of the translation used, while the second element identifies the version through which the text was actually consulted or cited.

A form such as “(Porro 2002)” should instead be avoided when the content under discussion belongs to Thomas Aquinas. A reference of this kind risks presenting the translator as the author of the philosophical content cited.

If the same translation is used systematically throughout the thesis, it is preferable to state this once, at the beginning of the thesis or at the first relevant occurrence. For example, one may use a formula such as:

• “Unless otherwise indicated, translations of the De ente et essentia follow Porro (2002).”

After this statement, subsequent references can normally be limited to the canonical reference:

• (Thomas Aquinas, De ente, chap. 2).

The translator and the page of the translation should be given again when they are useful for checking the exact wording of the passage or when different translations of the same work are used.

Note that the modern translation used must also appear in full in the Primary Sources section of the final bibliography.

Manuscripts

Manuscripts do not follow the author-date system. They must instead be identified through place, library, shelfmark, and folio. For example:

• (BnF, MS lat. 14859, fol. 233va–b)
• (Oxford, Bodl. Lib., MS Bodley 483, fols 82r–117v)

If manuscripts are used in the thesis, they must appear in a separate section of the bibliography devoted to manuscripts, in which institutions are given in full. For example:

• Paris, Bibliothèque nationale de France, MS fonds latin 14859.
• Oxford, Bodleian Library, MS Bodley 483.

The abbreviations r and v are used for recto and verso. When necessary, columns are indicated as ra, rb, va, and vb.

THE FINAL BIBLIOGRAPHY

When the thesis uses primary sources or manuscripts, the final bibliography must be divided into sections. The structure is as follows:

1. Manuscripts
2. Primary Sources
3. Secondary Literature

This division allows the reader to distinguish immediately between the documentary basis of the research and the interpretative literature.

Secondary literature

Modern scholarship uses the author-date system, and references must be included in the “Secondary Literature” section of the bibliography. It is important to keep in mind, however, that different types of publication (monographs, articles, and so on) follow different reference formats: the precise form varies according to the type of publication.

Monograph

Monographs are books written entirely by one or more authors, unlike edited volumes, which collect contributions by different authors. In the bibliography, the entry contains, in this order: the author’s surname and first name, year of publication, title of the book in italics, place of publication, and publisher.

• In the text: (Brower 2014)
• In the bibliography: Brower, Jeffrey E. 2014. Aquinas’s Ontology of the Material World: Change, Hylomorphism, and Material Objects. Oxford: Oxford University Press.

Journal article

The title of the article is placed within double quotation marks, while the title of the journal is in italics. This is followed by the volume number, the issue number where applicable, and the complete page range of the article.

• In the text: (Friedman 2021)
• In the bibliography: Friedman, Russell L. 2021. “Is Matter the Same as Its Potency? Some Fourteenth-Century Answers”. Vivarium 59/1–2: 123–142.

Chapter in an edited volume

A chapter in an edited volume is a contribution written by an author and published in a volume edited by one or more scholars, which collects contributions by different authors. In this case, the title of the chapter, placed within double quotation marks, must be clearly distinguished from the title of the volume, placed in italics. The editor or editors of the volume and the complete page range of the chapter must also be given.

• In the text: (Charles 2018)
• In the bibliography: Charles, David. 2018. “Physics I.7”. In Aristotle’s Physics Book I: A Systematic Exploration, edited by Diana Quarantotto. Cambridge: Cambridge University Press, 178–205.

Edited volume

When the volume as a whole is cited, the entry is constructed on the basis of the editors:

• In the text: (Mousavian and Fink 2020)
• In the bibliography: Mousavian, Seyed N., and Jakob Leth Fink, eds. 2020. The Internal Senses in the Aristotelian Tradition. Cham: Springer.

The indication “eds.” shows that Mousavian and Fink are the editors of the volume rather than the authors of a monograph. If a single chapter contained in the volume is used instead, the author of that chapter must be cited and the corresponding entry must follow the model given above for chapters in edited volumes.

It is important not to confuse these two situations. If, for example, the thesis discusses an argument presented by a single author in a chapter of an edited volume, the reference must be to the chapter rather than generically to the volume in which it appears.

Primary sources in the bibliography

Premodern primary sources must appear in a separate section of the bibliography entitled “Primary Sources”. This section always identifies the edition actually used in the thesis and, where relevant, the translation.

The difference from secondary literature is fundamental. In the main text, a medieval source is normally identified through author, work, and canonical reference:

• (Thomas Aquinas, In Phys. I, 118 [9], 59)

The bibliography, by contrast, specifies the modern edition through which the text was consulted and also gives the abbreviation, if one has been used in the thesis:

• Thomas Aquinas. In octo libros Physicorum Aristotelis expositio (= In Phys.). Edited by Mariano Maggiolo. Turin and Rome: Marietti, 1965.

A critical edition can be given in the same way:

• Duns Scotus, John. Lectura in librum secundum Sententiarum, distinctiones 7–44. Edited by the Commissio Scotistica. Opera omnia 19. Vatican City: Typis Vaticanis, 1993.

In the text, however, the source continues to be cited through the internal divisions of the work:

• (Duns Scotus, Lectura II, d. 12, q. 1, n. 24)

The same principle applies to a primary source accompanied by a translation. For example:

• In the text: (Thomas Aquinas, De ente, chap. 2; trans. Porro 2002)
• In the bibliography: Thomas Aquinas. L’ente e l’essenza (= De ente). Introduction, translation, notes, and apparatus by Pasquale Porro. Milan: Bompiani, 2002.

Primary sources must be ordered alphabetically according to the name of the historical author. When several editions of the same work are used, each must be listed separately. If the work is anonymous, the entry is alphabetised by title.

FORMAL ASPECTS

Quotation marks and quotations

Short quotations always use double quotation marks:

• “prime matter is pure potency”.

Single quotation marks are reserved for a quotation within another quotation:

• “Aquinas describes this as ‘knowledge by analogy’ in his commentary”.

Guillemets («…») must not be used, even in theses written in Italian. If a source uses a different system of quotation marks, it should be normalised according to these conventions when the quotation is incorporated into the text of the thesis.

Long quotations (more than three lines in the main text) must be presented as block quotations and do not require quotation marks. In this case, the long quotation:

• must use a font one size smaller than the main body text;
• must be indented by one centimetre from the left.

Omissions within a quotation must be indicated with square brackets: […]. Additions or clarifications by the author of the thesis must likewise be placed within square brackets.

Footnotes

Since bibliographic references are normally inserted in the main text, footnotes are not used to contain the ordinary secondary bibliography. They should therefore be used mainly for clarifications that would interrupt the flow of the argument too much, useful but non-essential secondary discussions, textual or editorial clarifications, and specific information about sources.

Artificial intelligence and bibliography checking

Artificial intelligence tools can be useful as an additional stage in proofreading the bibliography, but they must be used with particular caution. An appropriate use consists in providing AI with a bibliography that has already been prepared and asking it to flag possible problems, such as inconsistencies in punctuation, names written in different forms, missing years, differently formatted page ranges, or entries that appear not to follow the chosen style. Every suggestion must then be checked by the author against the original source before it is accepted.

AI must not instead be used to construct the bibliographic system, invent or complete missing data on the basis of assumptions, or autonomously transform the bibliography into a new “clean file”. A complete rewriting makes it much more difficult to distinguish the original data from changes introduced by the system and may conceal errors, omissions, or non-existent references.

Always remember that AI is a tool: ultimate responsibility for bibliographic and conceptual errors, plagiarism, and other forms of academic misconduct remains with the student.