datisi

Century Dictionary and Cyclopedia

1. n. The mnemonic name given by Petrus Hispanus to that mood of the third figure of syllogism in which the major premise is universal and affirmative, and the minor premise and conclusion are particular and affirmative. These distinctions of quantity and quality are indicated by the vowels of the word, a-i-i. The letter 8 after the second vowel shows that the mood is reduced to direct reasoning by the simple conversion of the minor, and the initial d shows that the resulting mood is darii. The following is an example of a syllogism in datisi: All men irrationally prejudiced have weak minds; but some men irrationally prejudiced are learned; hence, some learned men have weak minds.