45. Syllogistic Form, Matter, and Demonstration versus Dialectic
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Lecture Notes
Main Topics #
The Form versus Matter of a Syllogism #
- Form: Whether a conclusion follows necessarily from given premises (the logical structure)
- Matter: Whether the premises themselves are true or false, necessary or probable
- A syllogism can have correct form but false matter, or correct form and true matter
- The distinction is crucial for understanding both logic and theology
The Arithmetic Analogy #
Berquist illustrates the form/matter distinction through the example of multiplying numbers:
- Form: Performing multiplication correctly (the mathematical operation)
- Matter: Having the correct numbers to multiply (actual quantities)
- One can multiply correctly with wrong numbers (correct form, wrong matter)
- One can have correct numbers but multiply incorrectly (correct matter, wrong form)
- Both components are necessary for a correct result
Demonstration (Scientia) versus Dialectical Syllogism #
Demonstration #
- Premises are seen as necessarily true
- Either evident in themselves (axioms, postulates) or derived through prior demonstrations
- Example: Euclid’s geometry—axioms like “all right angles are equal” and “the whole is greater than the part”
- The conclusion is necessarily true when it follows from necessarily true premises
- Demonstrates not only that something is so, but why it must be so (knowledge of the cause)
Dialectical Syllogism #
- Premises are seen as probable opinions (endoxa)
- Conclusion follows necessarily in form, but is only probable in matter
- The conclusion is necessarily probable (follows necessarily from probable premises)
- Does not prove that something is necessarily true, only that it is probably so
Definition of Probable Opinion (endoxa) #
According to Aristotle, an opinion is probable because of:
- Quantity of men holding it: All men or most men think it
- Quality of men holding it: All or most men famous in a particular art or science, when speaking of matters pertaining to that art or science
- Example: Doctors’ opinions about smoking and health
- Example: Euclid’s opinions about geometry
The Conversion of Universal Negative Propositions #
Berquist establishes that “No A is B” necessarily entails “No B is A” through reductio ad absurdum:
- Assume “No A is B” but “Some B is A”
- Call the B that is A by the name X
- Then X is both B and A
- Therefore “Some A is B”
- This contradicts “No A is B”
- Therefore, we must accept “No B is A”
- This principle holds even for singular propositions (e.g., “Socrates is not a woman” entails “No woman is Socrates”)
Syllogistic Figures and Validity #
Berquist discusses converting premises to achieve valid forms:
- Not all figures equally make conclusions evident
- First figure is clearest: premises can be directly applied
- Other figures may require conversion to reduce to first figure form
- Example: “No B is C” and “Every A is B” requires conversion to establish “No C is A” clearly
Science as Reasoned-Out Knowledge #
Berquist defines scientia (science) as:
- Reasoned-out knowledge of things
- Not merely facts, but understanding through reasoning
- Includes thinking out, making distinctions, divisions, definitions, picking out statements, and forming conclusions
- Distinguished from modern experimental science, though both involve reasoning
Modern Science and Hypothesis #
Berquist discusses Einstein’s characterization of scientific hypotheses:
- Einstein said hypotheses in science are “freely imagined”
- Great discoveries often made by young scientists (20s-40s) with free imagination
- The testing of hypotheses occurs through prediction: if hypothesis is true, then certain phenomena should follow
- This is not identical to the syllogistic form of demonstration
- Example: Newton (light as particles) versus Huygens (light as waves) and the later photoelectric effect showing light behaves as both
- Young physicists like Heisenberg and Bohr made breakthrough discoveries through insight combined with rigorous reasoning
Key Arguments #
The Conversion of Negatives (Reductio ad Absurdum) #
- Assume “No A is B” but concede “Some B is A”
- Let X be a B that is A
- Then X is both A and B
- So there exists an A that is B
- This contradicts our premise
- Therefore, “No B is A” must be true
The Equality of Vertical Angles (Geometric Demonstration) #
- When two straight lines intersect, they form angles
- Each angle plus its adjacent angle equals two right angles (from the definition of a right angle)
- So: a + x = 2 right angles AND b + x = 2 right angles
- Therefore: a + x = b + x
- Subtracting equal things from equal things yields equal results
- Therefore: a = b (vertical angles are equal)
Form versus Matter in Validity #
- A syllogism with correct form makes its conclusion follow necessarily from its premises
- If the premises are true, the conclusion must be true
- If the premises are false or merely probable, the conclusion is still only as certain as the premises allow
- Therefore, correct form is necessary but not sufficient for knowledge of truth
Important Definitions #
Demonstratio #
A syllogism with necessarily true premises that produces a necessarily true conclusion, providing understanding of the cause of what is demonstrated.
Dialectical Syllogism #
A syllogism with probable premises (endoxa) that produces a conclusion that is necessarily probable but not necessarily true.
Endoxa #
Probable opinions—statements held by all or most people, or by all or most experts in a given field, regarding matters pertaining to that field.
Prior Analytics #
Aristotle’s logical treatise concerning the form of the syllogism (using letters rather than concrete examples), which asks whether something follows necessarily given certain premises.
Scientia #
Reasoned-out knowledge of things through demonstrations; knowledge of both the fact and the cause.
Examples & Illustrations #
The Ice Cream Cone Calculation #
- Berquist was at the beach with 19 grandchildren and adults needing ice cream
- Had to multiply: (number of people) × (cost per cone) = total cost
- Correct form: performing multiplication correctly
- Correct matter: knowing actual cost and actual number of people
- Either could be wrong independently
Geometric Examples #
- Vertical Angles: When two straight lines intersect, opposite angles are equal
- Demonstrated through the definition of right angles and the axiom that equal things subtracted from equal things are equal
- Material Universals: No animal is a stone, No cat is a stone, No tree is a stone
- These premises are all true, but they don’t necessarily entail “Every cat is an animal”
- Shows that true premises don’t guarantee a conclusion follows necessarily if the form is invalid
Famous Figures and Probable Opinions #
- Einstein on scientific hypotheses: His statement that hypotheses are freely imagined is probable because Einstein is famous in physics
- Mozart on opera: Mozart is famous for operas and says words must be secondary to music—his opinion on opera composition is probable
- Euclid’s Elements: Euclid’s geometric theorems carry weight because he is famous in geometry
The Nature of Light #
- Newton hypothesized light is particles (corpuscles)
- Huygens hypothesized light is waves
- Experiments showed light behaves as waves
- Einstein showed photoelectric effect only explained by particle hypothesis
- Light seems to be both waves and particles—a genuine puzzle about nature, not about reasoning
Philosophical Application #
- Pythagoras claimed not to be wise (sophos) but rather a lover of wisdom (philosophos)
- God is wise (He is wisdom itself) in the most absolute sense, yet can be called a “lover of wisdom” analogously
- The word “philosopher” itself indicates one who recognizes he lacks the complete wisdom of God
Questions Addressed #
How does the form of a syllogism differ from its matter? #
- Form: The logical structure—whether a conclusion necessarily follows from premises
- Matter: The truth or probability of the premises themselves
- Both are necessary: correct form ensures logical validity; correct matter ensures true conclusions
Can one validly convert “No A is B” to “No B is A”? #
- Yes, necessarily
- Denying this leads to contradiction: if some B were A when no A is B, then we’d have both A being B and A not being B
- This principle applies even to singular statements (e.g., “Socrates is not a woman” ↔ “No woman is Socrates”)
What is the difference between demonstration and dialectical syllogism? #
- Difference in form: None—both follow the rules of syllogistic logic
- Difference in matter: Demonstration uses necessarily true premises; dialectic uses probably true premises
- Result: Demonstration yields necessary knowledge; dialectic yields probable knowledge
Is modern science (as exemplified by Einstein) reasoned-out knowledge? #
- Yes, though it involves more than pure demonstration in the Aristotelian sense
- Scientific hypotheses involve free imagination, but they are tested through reasoning
- When predictions drawn from hypotheses are confirmed by experiment, this provides probable support
- But the confirmation is not quite syllogistic—it’s the affirmation of the consequent (if P then Q; Q is true; therefore P)
How can different scientific theories (particle vs. wave) both be supported by evidence? #
- This suggests that reality itself may be more complex than classical logic accommodates
- It indicates the need for deeper understanding, as both properties seem to inhere in the same subject
- Modern quantum mechanics eventually developed the concept of complementarity to address this
Notable Quotes #
“I’m from Missouri. How do you know you can turn that around, huh?” — Berquist, challenging a student’s assumption about converting negatives
“You’re forced by the truth itself, right?” — Berquist, explaining how reductio ad absurdum compels assent
“The difference between demonstration and dialectic right is in the form or in the matter?” — Berquist’s core question distinguishing the two types of syllogisms
“The words must be all together to obedience [to music].” — Mozart, cited by Berquist on opera composition (probable opinion from an expert)
“Don’t call me wise. God alone is wise.” — Pythagoras, cited to illustrate how even the word “philosopher” (lover of wisdom) properly indicates one aware of lacking God’s wisdom