MODULE 3
valid deductive argument
an argument in which it is impossible for the conclusion to be false given that the premises are true
weak inductive argument
an argument in which the conclusion does not follow probably from the premises, even though it is claimed to
strong inductive argument
an inductive argument in which it is improbable that the conclusion be false given that the premises are true I.e., The conclusion is probably true assuming the premises are true.
cogent argument
an inductive argument that is strong and has all true premises.
uncogent argument
an inductive argument that is weak, has one or more false premises, fails to meet the total evidence requirement, or any combination of these.
As an illustration of the need for the total evidence requirement, consider the following argument: Swimming in the Caribbean is usually lots of fun. Today the water is warm, the surf is gentle, and on this beach there are no dangerous currents. Therefore, it would be fun to go swimming here now. If the premises reflect all the important factors, then the argument is cogent. But if they ignore the fact that several large dorsal fins are cutting through the water (suggesting sharks), then obviously the argument is not cogent.
.
The following argument is deductive. Evaluate this argument for validity first and soundness afterward, then use the selection lists beneath each argument to indicate the answers that fit best. Since Alaska is not a part of the contiguous United States, it follows that Alaska shares a border with another state.
This argument is invalid and does not haves all true premises. Therefore, the argument is unsound
Choose the answer that best defines the following term: Invalid Argument a. A deductive argument in which it is possible for the conclusion to be false even if the premises are true. b. A deductive argument in which it is impossible for the conclusion to be false given that the premises are true. c. An inductive argument in which it is improbable that the conclusion be false given that the premises are true. I.e., The conclusion is probably true assuming the premises are true. d. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so.
a
Choose the answer that best defines the following term: Valid Argument a. A deductive argument in which it is impossible for the conclusion to be false given that the premises are true. b. A deductive argument in which it is possible for the conclusion to be false even if the premises are true. c. A deductive argument based on facts with true premises. d. An inductive argument that has a true conclusion.
a
Consider the following scenario and then answer the corresponding question by applying the definitions of strength and cogency to each scenario. (When answering the question, you can assume that the total evidence requirement has been met in each case.) Suppose you have a strong argument that has false premises. Given this information, what do you know about the conclusion of this argument? A. The conclusion is probably false. B. The conclusion may be either true or false. C. The conclusion must be true. D. The conclusion is probably true. E. The conclusion must be false.
a WRONG
Choose the answer that best describes the attributes of the following argument: If Ricky Bobby runs fast, then Bucky shaves his face. Bucky shaved his face. Thus, Ricky Bobby runs fast. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
a WRONG c
invalid deductive argument
a deductive argument in which it is possible for the conclusion to be false given that the premises are true
unsound argument
a deductive argument that is invalid, has one or more false premises, or both.
sound argument
a deductive argument that is valid and has all true premises.
Choose the answer that best defines the following term: Cogent Argument a. An Inductive argument that is strong and has all true premises. b. A deductive argument that is valid and has all true premises. c. A deductive argument in which it is impossible for the conclusion to be false given that the premises are true. d. An inductive argument in which it is improbable that the conclusion be false given that the premises are true. I.e., The conclusion is probably true assuming the premises are true.
a.
Choose the answer that best describes the attributes of the following argument: All humans are mortal. Socrates is human. Therefore, Socrates is mortal. a. Sound b. Unsound c. Cogent d. Uncogent
a. sound
Consider the following inductive argument, and evaluate for inductive strength. To do this, begin by assuming that the argument's premises are true (even if they are false). Then ask yourself whether the conclusion would therefore probably be true as well. If the answer to this question is yes, then the argument is strong. If the conclusion is not likely to be true based upon the given premises, then the argument is weak. The label on the side of a certain soda can indicates that the can was manufactured by Ball Corporation in their plant in Fairfield, California. Based on the information on the can's label, it is unlikely that the can was manufactured by any company other than Ball Corporation. a. strong b. weak
a. strong
Choose the answer that best defines the following term: Sound Argument a. A deductive argument that is either invalid, has one or more false premises, or both. b. A deductive argument that is valid and has all true premises. c. An inductive argument in which it is improbable that the conclusion be false given that the premises are true. d. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so.
b
Choose the answer that best defines the following term: Unsound Argument a. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so. b. A deductive argument that is either invalid, has one or more false premises, or both. c. A deductive argument that is valid and has all true premises. d. An inductive argument in which it is improbable that the conclusion be false given that the premises are true
b
Consider the following deductive argument and evaluate it for validity. To do this, begin by assuming that each argument's premises are true (even if they are false). Then ask yourself whether the conclusion also would have to be true. If the answer to this question is yes, then the argument is valid. If the conclusion still could be false when you assume that the premises are true, then the argument is invalid. Since x times y equals 15, and y equals 5, it follows that x equals 4. A. Valid B. Invalid
b
Choose the answer that best describes the attributes of the following argument: All US presidents have been women. Thus, it is more than likely the case that the next US president will be a woman. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
b WRONG
Choose the answer that best describes the attributes of the following argument: The sign on the front of the college located at 3209 Virginia Avenue, Fort Pierce, FL. 34981 says Indian River State College. Thus, I have good reason to think that it is in fact IRSC. a. Deductive and Cogent b. Inductive and Cogent c. Deductive and Sound d. Inductive and Sound
b WRONG c
Choose the answer that best defines the following term: Weak Argument a. An inductive argument in which it is improbable that the conclusion be false given that the premises are true. I.e., The conclusion is probably true assuming the premises are true. b. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so. c. A deductive argument in which it is possible for the conclusion to be false even if the premises are true. d. An inductive argument that proceeds from the knowledge of a selected sample to some claim about the whole group.
b.
Choose the answer that best defines the following term: Uncogent Argument a. A deductive argument that is either invalid, has one or more false premises, or both. b. A deductive argument in which it is possible for the conclusion to be false even if the premises are true. c. An inductive argument that is either weak, has one or more false premises, or both. d. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so.
c
Consider the following scenario and then answer the corresponding question by applying the definitions of validity and soundness. Select the best answer. Suppose you have a valid argument with a false conclusion. Given this information, what do you know about the truth value of the argument's premises? A. The premises may be any combination of true and false. B. There must be at least one true premise and at least one false premise. C. At least one premise must be false. D. The premises must all be true. E. The premises must all be false.
c
Suppose you have a deductive argument with a true conclusion. Given this information, what do you know about the soundness of this argument? A. The argument must be unsound. B. The argument may be either sound or unsound. C. The argument must be sound. D. The argument is almost sound. E. The argument is both sound and unsound.
c
Choose the answer that best describes the attributes of the following argument: It has snowed every year in recorded history. Thus, it will probably snow this year. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
c.
Choose the answer that best describes the attributes of the following argument: The last US president was a man. Thus, the next US president will probably be a man. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
c. WRONG
Choose the answer that best describes the attributes of the following argument: Florida is located in China. Fort Pierce is located in Florida. Therefore, Fort Pierce is located in China. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
d
Choose the answer that best describes the attributes of the following argument: Polar bears are white and live in the Arctic. Albino penguins are white. Hence, albino penguins probably live in the Arctic as well. a. Deductive and Valid b. Deductive and Invalid c. Inductive and Strong d. Inductive and Weak
d
Consider the following scenario and then answer the corresponding question by applying the definitions of validity and soundness. Select the best answer. Suppose you have an invalid argument with a true conclusion. Given this information, what do you know about the premises of this argument? A. The premises must all be true. B. The premises may be any combination of true and false. C. There must be at least one false premise. D. The premises must all be false. E. The premises must all have the same truth values.
d WRONG
Choose the answer that best describes the attributes of the following argument: All tacos are made with used tires. Taco bell makes tacos. Thus, Taco Bell tacos are made with used tires. a. Deductive, Valid, and Sound b. Deductive, Valid, and Unsound c. Deductive, Invalid, and Sound d. Deductive, Invalid, and Unsound
d WRONG a
Choose the answer that best defines the following term: Strong Argument a. An inductive argument in which it is improbable that the conclusion be false given that the premises are true. I.e., The conclusion is probably true assuming the premises are true. b. An inductive argument in which the conclusion does not follow probably form the premises even though it is claimed to do so. c. A deductive argument that is valid and has all true premises. d. A deductive argument in which it is impossible for the conclusion to be false given that the premises are true.
d WRONG b
Choose the answer that best describes the attributes of the following argument: If one fails to pay taxes, then they will be fined. John failed to pay his taxes. Thus, John will be fined. a. Deductive and Invalid b. Deductive and Valid c. Inductive and Strong d. Inductive and Weak
d WRONG b
Choose the answer that best describes the attributes of the following argument: 90% of the people in the world are at least 7 feet tall. I have never met Shaquille O'Neil; however, I know he is a person. Thus, he must be at least 7 feet tall. a. Inductive, Strong, and Cogent b. Inductive, Strong, and Uncogent c. Inductive, Weak, and Cogent d. Inductive, Weak, and Uncogent
d. WRONG b
Choose the answer that best describes the attributes of the following argument: If you eat an egg, then you will consume some protein. Thus, if you did not consume some protein, then you did not eat an egg. Deductive and Sound Deductive and Unsound Deductive and Cogent Deductive and Uncogent
deductive and sound
Suppose you have a strong argument with a false conclusion. Given this information, what do you know about the premises of this argument? A. The premises are probably false. B. The premises are probably true. C. The premises must all be false. D. The premises must all be true. E. The premises may be any combination of true and false.
e
Suppose you have an argument with false premises and a false conclusion. Given this information, what do you know about the validity of this argument? A. The argument is almost valid. B. The argument must be invalid. C. The argument is both valid and invalid. D. The argument may be either valid or invalid. E. The argument must be valid.
e
The following argument is deductive. Evaluate this argument for validity first and soundness afterward, then use the selection lists beneath each argument to indicate the answers that fit best. Since the moon orbits the earth every 13 days, it follows that the moon will orbit the earth at least three times every month.
invalid, does not have, unsound
One more time. Determine whether the following argument is a deductive argument or an inductive argument. If the argument is a deductive argument, then evaluate the argument for its validity and soundness. If the argument is an inductive argument, then evaluate the argument for its strength and cogency. In the first slot assess for validity or invalidity only. In the second slot assess for validity, invalidity, strength, and weakness only. In the third slot assess for soundness, unsoundness, cogency and uncogency only. The Sierra Nevada mountain range and the island of Jamaica are both popular tourist destinations. Since February is a good month for skiing in the Sierra Nevada region, it follows that if you are traveling to Jamaica in February, then you should bring your ski equipment.
this argument is inductive, weak, uncogent
The following arguments is an inductive. Evaluate the argument for strength first and cogency second, then use the selection lists beneath each argument to indicate your answers. You can assume that each argument meets the total evidence requirement. In the United States, it costs more in postage to mail a letter to China than it costs to mail a letter domestically. So, since Canada is similarly an overseas country just like China, it is likely that it also costs more in postage to mail a letter to Canada than it costs to mail a letter domestically.
weak, does not have, uncogent
