  Discussions of singular terms were frequently related to a passage from Porphyry’s Isagoge. In the version used by medieval logicians, Porphyry writes: “Individual is said of one particular alone. Socrates is said to be individual, and this white &lt;thing&gt;, and this approaching &lt;person&gt;, and son of Sophroniscus, if Socrates be his only son. Such things are said to be individuals, since each of them consists of properties whose collection will never be the same in another.” 