For accident is not the subject of accident; because no form can be a subject, since to be a subject is a property of matter.
 Thomas Aquinas, Summa Theologica (1274). copy citation

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Author Thomas Aquinas
Source Summa Theologica
Topic property accident
Date 1274
Language English
Reference
Note Translated by Fathers of the English Dominican Province
Weblink http://www.gutenberg.org/cache/epub/19950/pg19950-images.html

Context

“Whether in This Sacrament the Dimensive Quantity of the Bread or Wine Is the Subject of the Other Accidents? Objection 1: It seems that in this sacrament the dimensive quantity of the bread or wine is not the subject of the other accidents. For accident is not the subject of accident; because no form can be a subject, since to be a subject is a property of matter. But dimensive quantity is an accident. Therefore dimensive quantity cannot be the subject of the other accidents. Obj. 2: Further, just as quantity is individuated by substance, so also are the other accidents.” source