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English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1
Syllogisms
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 2
Definition
• Syllogism—declarative statements formulated in such a fashion to defend an argument.
• Aristotle created the concept when he was developing his theories on rhetoric and the use of logical arguments.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 3
Premise
• A premise is a statement that can be agreed upon as an established truth.
• When two premises are connected as a defense to your argument, and they in turn result in a resolution or a firm closure to your argument, the final product is considered a syllogism.
• Keep in mind this basic formula is based upon a three proposition system.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 4
Premises > Syllogism
• An ancient syllogism created by Aristotle reads which is often quoted:
Major Premise: All humans are mortal.
This is an established truth which cannot
be argued.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 5
Premises > Syllogism
• An ancient syllogism created by Aristotle reads which is often quoted:
Major Premise: All humans are mortal.Minor Premise: Socrates is a human being.
Again, the minor premise is a fact which cannot be argued.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 6
Premises > Syllogism
• An ancient syllogism created by Aristotle reads which is often quoted:
Major Premise: All humans are mortal.Minor Premise: Socrates is a human being.Conclusion: Socrates is mortal.
What results is a quick, basic display of logic deduction used to conclude an observation.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 7
Valid or Invalid
In the end, a syllogism can be considered valid or invalid.
• Such labels are based upon the use of (il)logical reasoning which construct Major and/or Minor Premises.
As writers, one has to be careful crafting these formulas for defense. It is easy to generate flawed logic or invalid syllogisms within rhetoric strategies.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 8
An invalid syllogism
Major premise:
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 9
An invalid syllogism
Major premise: All snakes are cold-blooded.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 10
An invalid syllogism
Major premise: All snakes are cold-blooded.
Minor premise:
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 11
An invalid syllogism
Major premise: All snakes are cold-blooded.
Minor premise:All snails are cold-blooded.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 12
An invalid syllogism
Major premise: All snakes are cold-blooded.
Minor premise:All snails are cold-blooded.
Conclusion:
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 13
An invalid syllogism
Major premise: All snakes are cold-blooded.
Minor premise:All snails are cold-blooded.
Conclusion:Therefore, all snails are
snakes.
—which of course is not a valid closure.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 14
Invalid Syllogism
In this case, the two truths when brought together result in an erroneous logic.
• These types of flawed logic become the foundation for stereotypes and
libelous statements.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 15
Invalid Syllogism
The concept for you to take away from this part of the discussion: • Be sure the formulas you construct resulting in your final conclusion follow a basis of producing a sound argument. • Avoid fallacies in your syllogism
construction.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 16
Thomas Jefferson
Thomas Jefferson uses the classical tradition of constructing his argument by using valid syllogisms within the Declaration of Independence (in both drafts of the document supplied to you).
• Look at the opening section of his statement, the Preamble.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 17
Thomas Jefferson
In the finished draft, the Preamble of the Declaration reads:
We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness. —That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, —That whenever any Form of Government becomes destructive of these ends, it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness. (Declaration of Independence)
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 18
Thomas Jefferson
Major Premise: We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
Minor Premise: — That to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, —That whenever any Form of Government becomes destructive of these ends,
Conclusion: it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 19
Thomas Jefferson
When first constructing these defenses, think in terms of if, then, therefore statements.
Again, using the Declaration as an example, notice the implied use of the words: “if,” “then,” and “therefore.”
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 20
Thomas Jefferson
Major Premise: (If) We hold these truths to be self-evident, that all men are created equal, that they are endowed by their Creator with certain unalienable Rights, that among these are Life, Liberty and the pursuit of Happiness.
Minor Premise: — (Then […] ) to secure these rights, Governments are instituted among Men, deriving their just powers from the consent of the governed, —That whenever any Form of Government becomes destructive of these ends,
Conclusion: (Therefore) it is the Right of the People to alter or to abolish it, and to institute new Government, laying its foundation on such principles and organizing its powers in such form, as to them shall seem most likely to effect their Safety and Happiness.
English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 21
Thomas Jefferson
A further examples from the Declaration:
Major premise: (If) When in the course of human events it becomes necessary for one people to dissolve the political bands which have connected them with another
Minor premise: ( […] then) to assume among the powers of the earth the separate and equal station to which the laws of nature and of nature's God entitle them,
Conclusion: (therefore) a decent respect to the opinions of mankind requires that they should declare the causes which impel them to the separation.
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