For some philosophical or classical works, typical citation conventions may not apply. For many ancient and medieval, as well as some early modern philosophers there are specific abbreviations and style conventions that scholarly research must adhere to. These abbreviations may be specific to certain journals or publications, for example The Journal of Nietzsche Studies has its own standards, but in general there are some conventions that adhere to a more or less standard system.
For example:
Descartes: Almost all journals (English, French, and other) require all citations to be of the following ‘complete works’ edition and translation. And it is always abbreviated “AT”, followed by the title of the text, vol. no., and page.
Reference:
RENE DESCARTES, Oeuvres de Descartes, Charles Adam & Paul Tannery (eds.), (Nouvelle présentation, en co-édition avec le Centre national de la recherche scientifique), 11 vols., J. Vrin, Paris 1957-1974. (AT in citations.)
When you are writing a research paper on religious or philosophical studies, consult with your instructor, or the journal you seek to contribute to, in order to learn their professional preference for your submission. While the philosophy department at ETSU generally uses Chicago Notes and Bibliography, philosophy as a discipline does not adhere to any one style convention.