SYLLOGISTIC FIGURESFigure 1 (Sub – Pre) M–T A dog is an animal. t–M But a puppy is a dog. t–T :. A puppy is an animal.Take note of the location of the M
Figure 2 (Pre – Pre) T–M Every man is a thinker. t–M But a fish is not a thinker. t–T :. A fish is not a man. Note: focus on the location of the M
Figure 3 (Sub – Sub) M–T Some vegetables are cabbages. M–t But all vegetables are plants. t –T :. Some plants are cabbages. Note: Where’s the M?
Figure 4 (Pre – Sub) T – M Some Filipinos are Igorots. M – t But all Igorots are God-created. t – T :. Some God-created beings are Filipinos. Again note the location of M
Principles of Categorical Syllogism1. Principle of Reciprocal Identity Briefly expressed: A is B God is divine. But C is B. But Jesus is divine. :. A is C. :. God is Jesus.
2. The Principle of Reciprocal Non –IdentityBriefly expressed:A is B. All plants are livingthings.But c is not A. But stones are notplants.:. C is not B. :. Stones are notliving things.
3. The Principle of Dictum de Omni What is affirmed universally of agiven term is affirmed of everythingfound within the extension of saidterm.For instance what is affirmed of theterm “creature” can be affirmed ofman, animals and plants which areextension ideas of the idea creature.If creatures are mortal then man,animals and plants are _______.
4. The Principle of Dictum de Nullo Opposite of dictum de omni. What is negated universally of a given term is likewise negated of every term found within the extension of the said term. If a plant is not a stone all extension ideas of the idea plant is not a stone.
5. The Principle of Contradiction If a THING IS, it cannot be IS NOTat the same time. If this is a table,then it cannot be that this is not a tableat the same time.
Basic Rules of CategoricalSyllogism 1. There must be only three (3) univocal terms. 2. There can be no two (2) negative premises. 3. On quality, if the 2 premises are affirmative the conclusion is affirmative. 4. The conclusion is negative if one of the premises is negative. 5. The conclusion must be particular if one of the premises is particular.
6. In terms of quantity, there must beno 2 particular premises. Onepremise must be at least universal.
VALIDITY and TRUTH IN SYLLOGISMTwo Conditions:1. Correct in form2. True in content.◦ A syllogism may be correct in form but false in content. Or may be incorrect in form but true in content. To be a valid categorical syllogism the form must be correct and the content must be true.