Who first devised the vowel-consonant designations in the taxonomy of syllogisms? (e.g. Barbara, Celarent, Darii, Ferio, etc.)

Question

In the history of philosophy & logic there is a taxonomy of syllogisms designated by name. William of Sherwood and Peter of Spain write of a mnemonic to help medieval students of logic memorize the syllogisms:

Barbara celarent darii ferio baralipton Celantes dabitis fapesmo frisesomorum; Cesare campestres festino baroco; darapti Felapton disamis datisi bocardo ferison.

Vowels & particular consonants have particular meaning.

• a – universalis affirmativa (i.e. affirmo)
• e – universalis negativa (i.e. nego)
• i – particularis affirmativa (i.e. affirmo)
• o – particularis negativa (i.e. nego)
• s – conversio simplex.
• p – conversio per accidens.
• c – reductio ad contradictionem
• m – metathesis (in Petrus Hispanus, conversio per contrapositionem?).
• B – reductio ad Modus Barbara.
• C – reductio ad Modus Celarent.
• D – reductio ad Modus Darii.
• F – reductio ad Modus Ferio.

Whom first devised the vowel-consonant designations in the taxonomy of syllogisms?

(A link to an article describing the context of logicians naming syllogisms mnemonically: https://plato.stanford.edu/entries/medieval-syllogism/)

Answer 1

The source is Medieval Logic.

According to :

• Joseph Maria Bochenski, A History of Formal Logic (1961), §32:

L. Minio-Paluello has recently made the big discovery of an early attempt to construct syllogistic mnemonics, in a MS of the early 13th century. [...]

This is a very primitive technique, but at least it shows that the highly developed terminology of Peter of Spain (who became Pope in 1276, under the name of John XXI; but see footnote : This can not have originated with him) had antecedents in Scholasticism itself.

See Summulae Logicales, Tractatus IV De Sillogismis, §13 (page 64v).

Thus the origin is probably unknown in the first half of 13th Century.

We found it "fully blown" into Petrus Hispanicus' standard textbook on logic, the Tractatus, called afterwards Summule logicales; see page 52.

Another source is William of Sherwood's logical treatise Introductiones in logicam, written in the middle of the 13th century.