Classical Logic Homework Phil 410
Classical Logic Homework Phil 410
PHL/410CLASSICAL LOGIC
FINAL EXAM
100 total points possible (29 questions plus an EC)
For multiple choice questions, fill in your answer with a color.Don’t use green or red, as I will use these to mark your answer right or wrong.
1. Which logician/philosopher proposed abduction as a method to resolve a problem?(1 Point)
A.Jürgen Habermas
B.Charles Peirce
C.Josiah Royce
D.George Boole
1 point
2.I took an new antibiotic last week and I got better fast.Clearly this new antibiotic is effective. .This conclusion is an example of: (1 point)
A.straw man
B.division
C.post hoc, propter hoc
D.appeal to ignorancel
1 point
4.The philosophy of Aquinas is nonsense.He was a bigoted Catholic theologian who would say anything as long as it agreed with Rome.
This is most clearly an example of:
A.argument from ignorance
B.appeal to authority
C.ad hominem
D.petitio principii
1 point
5.Since physical science cannot find its location or action, belief in a human soul is a dead letter.
A. argument against the man
B. composition
C. false cause
D. begging the question
1 point
6.Nancy Pelosi: Sanctuary cities are safer because undocumented aliens feel free to report crimes and testify without fear of being deported.
Carlos Tantara (Lt Gov of Florida) replies:I haven’t seen any data to back that up.
If Mr. Tantara’s suggestion is that what Ms. Pelosi said is false, he would be committing:
A. appeal to popular opinion (ad populum)
B. fallacy of ignorance
C. attack on the person (ad hominem)
D. begging the question (petitio principii)
All questions about Categorical Logic are to be answered from the Traditional or Aristotelian Logic of Categories, not the Boolean version.
7. What does Oab mean?
1 point
8. Which, if any, of the terms in Oab are distributed?
1 point
9.Identify 10 propositions that may be inferred by means of the square of opposition and other immediate inferences such as obversion, etc. starting with this given:
it is false that some snakes are vegetarian.
If you prefer you can do this in symbols, i.e., start with ~Isv, where ~ means “it is false that”.Name the inference rule in each case.For some of these you will have to use a two-step process of inference (e.g. contradiction then contrariety).Each of these steps should be written separately on different lines, as each uses a rule of inference itself.
For example, suppose the given were “All students are logical”, you might start by inferring “Some students are logical” by the rule subalternation.You would answer this way:
|
Inference # |
Inference |
Inference Rule |
|
0 |
All students are logical. |
Given |
|
1 |
Some students are logical |
From 0 by subalternation |
|
2 |
It is false that no students are logical. |
From 1 by contradiction |
You would continue on with many more inferences that you can get from the original given or from any of the derived steps you take.
OK, now let’s do the real problem.
|
Inference # |
Inference |
Inference Rule |
|
0 |
it is false that some snakes are vegetarian |
Given |
|
1 |
||
|
2 |
||
|
3 |
||
|
4 |
||
|
5 |
||
|
6 |
||
|
7 |
||
|
8 |
||
|
9 |
||
|
10 |
20 points
10.Suppose that Aab is false.Does that mean Eab is false too.Explain briefly.
2 points
11. What is the difference between contrary statements and contradictory statements.Give a pair as examples of each.
4 points
12.What does this diagram exhibit?
1 point
Syllogisms
13.Consider the syllogism:
No catfish are cats.
Some fish are catfish.
Therefore, No fish are cats.
13a.What is the major term?
13b.What is the minor term?
13c.What is the middle term?
13d.Is the syllogism in standard form?If not, what has to change to make it so?
13e.What is the mood?
13f.What is the figure?
13g.Is it valid?
13h.If it is invalid, give the rule it violates.If it is valid, give its medieval name.
9 points
14.Let’s change it around a little…
Consider the syllogism
No cats are fish.
All catfish are fish.
Therefore, No cats are catfish.
14a.What is the major term?
14b.What is the minor term?
14c.What is the middle term?
14d.Is the syllogism in standard form?If not, what has to change to make it so?
14e.What is the mood?
14f.What is the figure?
14g.Is it valid?
14h.If it is invalid, give the rule it violates.If it is valid, give its medieval name.
9 points
15. In order to put the following syllogism into standard form, you must change one of the premises.Which one, and how?Is the syllogism valid?If not, why not?
All snakes are vertebrates.
No reptilesare invetebrates.
No reptiles are snakes.
4 pomts
16.Here is a sophisticated philosophical argument from the 17th century Anglo-Irish philosopher, George Berkeley, an Anglican bishop who later moved to America.It is a syllogism, but it will take a bit of effort to analyze it and get it into standard form.It shows you how syllogisms can be used is real arguments, as opposed to the silly ones we learn syllogisms from in textbooks.
. . . because intense heat is nothing else but a particular kind of painful sensation; and pain cannot exist but in a perceiving being; it follows that no intense heat can really exist in an unperceiving corporeal substance.
—George Berkeley,Three Dialogues Between Hylas and Philonous, in Opposition to Sceptics and Atheists, 1713
16a. What is the conclusion?
16b. What is the predicate of the conclusion?
16c.What is the major premise?
16d.What is the minor premise?
16e.Which premise do you have to change to get this syllogism into standard form?And how?
16f.Write the analyzed syllogism?
16g.Is it valid?If not, what rule does it violate?
9 points
17. What is the figure, mood, and give an example of Felapton.
3 points
For 18-20, apply the six traditional or Aristotelian rules for checking syllogisms to validate or invalidate the following syllogisms.
Write Valid or Invalid, and write out the rule violated if invalid.
18.All sharks are fish.Some pelagic whitetips are fish.Therefore some sharks are pelagic whitetips.
2 points
19.No zebras are pachyderms.Some zebras are albinos.Therefore some albinos are pachyderms.
2 points
20.Some conditions caused by viruses are not dangerous.All cancers are dangerous.Therefore some cancers are not conditions caused by viruses.
2 points
21. Name a valid syllogism exhibited by the following diagram.Give a standard form example of it. Identify its figure and mood.Consider the horizontal hash marks to be the same thing as Xs.
4 points
Sentential Logic
24.Explain briefly the difference between inclusive and exclusive disjunction.
2 points
25.Write a valid modus ponens argument whose final conclusion is: Oxygen is an inflammatory substance.
4 points
26.Validly transform the following compound statement linked by the conjunction or intoone linked by the conjunction and.If you do this by steps, you can get partial credit for each correct step.
Trump will win the election or Clinton will not win the election.
4 points
27. Identify this argument type:
If a previously unknown fish is found whose skeleton is bony, the fish is not a shark.In fact its skeleton is bony, so this fish is not a shark.
A.Affirming the Consequent
B.Modus Ponens
C.Modus Tollens
D.Denying the Antecedent
2 points
28.Identify this argument type:
If the two parents of this child are both carriers of the gene for color-blindness, the child is color-blind , but the child’s mother is not color-blind.It follows that the child is not color-blind.
A.Affirming the Consequent
B.Modus Ponens
C.Modus Tollens
D.Denying the Antecedent
2 points
XX.What formal fallacy is abduction similar to?If that is so, what good is it?
3 points
29.Give an example of an argument that exemplifies affirming the consequent and has the following standalone 2nd premise:atoms are not the building blocks of nature.
4 points
Extra Credit 3 possible points
Construct a valid deductive argument with two true premises and a false conclusion.
