 The middle term may be (i) subject of the major premise and predicate of the minor premise; (ii) predicate of both; or (iii) subject of both. The resulting configurations are called (i) first figure (šakl awwal), (ii) second figure (šakl ṯānin), and (iii) third figure (šakl ṯāliṯ). Like Aristotle, Avicenna does not contemplate a fourth  figure.[14]  Each figure contains a number of valid moods (ḍurūb), identified by the quantity, quality, and modality of the premises and conclusion. For the sake of simplicity, I use standard vocabulary for the treatment of the Aristotelian syllogistic (in particular the list of mnemonic tags developed in the Latin middle ages for the identification of  moods).[15]  The moods of the first figure are Barbara, Celarent, Darii, Ferio. The moods of the second figure are Cesare, Camestres, Festino, Baroco. The moods of the third figure are Darapti, Felapton, Datisi, Disamis, Bocardo, and Ferison. Each of the above will be productive with certain combinations of modalized premises and not with others.