Form of a syllogism based on the Modus Darii, in which an affirmative existential proposition is inferred from two affirmative universal premisses. This form has an additional existential requirement.
All M are P.
All M are S.
[and there exists at least one M]*
Therefore, Some S are P.
For example:
All squares are rectangles.
All squares are polygons.
[and there exists at least one square]*
Therefore, Some polygons are rectangles.</span>
Modus Disamis is very similar to the modi Datisi and Disamis, except that it is based on two universal statements in the premisses, rather than a universal and an existential statement each.
The name “Darapti” is a mnemonic term that helps to remember the most important characteristics of this mode: The “D” at the beginning indicates that it is related to the Modus Darii, the two “a” and the “i” indicate that affirmative universal and existential statements make up this form.