Modus Fresison
Form of a syllogism based on the Modus Ferio, in which a negative existential proposition is inferred from negative universal and affirmative existential premisses.
No P is M. Some M are S. ∴ Some S are not P.
For example:
No circle is a rectangle. Some rectangles are squares. ∴ Some squares are not circles.
Modus Fresison is very similar to Modus Ferio, the only difference is that in both premisses the terms are swapped.
Name
The name “Fresison” is a mnemonic term that helps to remember the most important characteristics of this mode: The “F” at the beginning indicates that it is related to the Modus Ferio, while the vowels indicate the types of statements used in the form: “e” stands for a negative universal, the “i” for an affirmative existential premise, while the “o” indicates an affirmative existential conclusion.