syllogisms english 1301: composition & rhetoric i || d. glen smith, instructor 1

21
Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

Upload: philip-brendan-skinner

Post on 18-Dec-2015

220 views

Category:

Documents


2 download

TRANSCRIPT

Page 1: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

Syllogisms

Page 2: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 3: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 4: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 5: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 6: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 7: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 8: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 8

An invalid syllogism

Major premise:

Page 9: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 9

An invalid syllogism

Major premise: All snakes are cold-blooded.

Page 10: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 10

An invalid syllogism

Major premise: All snakes are cold-blooded.

Minor premise:

Page 11: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 12: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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:

Page 13: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 14: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 15: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 16: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 17: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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)

Page 18: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 19: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.”

Page 20: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.

Page 21: Syllogisms English 1301: Composition & Rhetoric I || D. Glen Smith, instructor 1

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.