An expression is vague if
there is no precise boundary between the cases in which it applies and the cases in which it does not apply.
Feedback: The co... [Show More] rrect answer is B. An expression is vague exactly when it lacks a precise meaning. A vague expression, in other words, is one without a sharp boundary between cases in which it applies and cases in which it does not apply. Some standard examples of vague terms are "bald," "tall," and "heap."
Which of the following expressions is vague?
hill
The correct answer is E.
Because there is no sharp boundary between things that are hills and things that are not hills, the term "hill" is vague. To see why the term "hill" is vague, just imagine a series of lumps on the ground, the first of which is very small, and each subsequent member of which is slightly larger than the last. At the beginning of the series, the lumps are definitely not hills. At some later point in the series, however, there are lumps, which definitely are hills. Yet there is no sharp, precise boundary between the hills and the non-hills. Between the items that are definitely hills and the items that are definitely not, there are many borderline cases. For this reason, the term "hill" is vague.
The terms "33," "=," "acceleration," and "mass" are not vague. Either a given number is 33, or else it is not. A number can not be a borderline case of 33; there are not numbers, which are 33 to various degrees. Likewise for mathematical equality. Either a pair of terms are equal, or else they are not. There is no such thing as varying degrees of mathematical equality.
Acceleration and mass, likewise, are non-vague concepts. There are, of course, various amounts of mass that a body can have, and also various rates of acceleration, but these facts do not mean that the concepts of mass and acceleration are themselves vague. From the fact that there are different amounts of mass, in other words, does not mean that something can have mass to different degrees. Either a thing has mass, or it doesn't. Having mass is an all-or-nothing affair. The question of how much mass one has, in other words, is different from the question of whether one has mass at all.
An expression is ambiguous if
it has two or more distinct meanings.
Feedback: The correct answer is A. An ambiguous expression is one, which has more than one distinct meaning. If the expression has multiple meanings because a single word has multiple meanings, then the ambiguity is semantic. If the expression, however, has multiple meanings because a larger phrase or clause has multiple meanings, then the ambiguity is syntactic.
Which of the following expressions is semantically ambiguous?
bank
Feedback:
The correct answer is A.
The term "bank" is semantically ambiguous. On one hand, the term can refer to the edge of a river, stream, or body of water. On the other hand, the term can also refer to a financial institution, which stores wealth.
Which of the following sentences is syntactically ambiguous?
Close doors and open windows.
Feedback:
The correct answer is A.
The phrase "close doors and open windows" could mean two different things. On one hand, it could be a command for people to close doors, and for people to open windows. On the other hand, it could be a command for people to close two sorts of things, namely doors and open windows. Because this ambiguity is not the result of a single term, such as "door," having multiple meanings, the ambiguity is syntactic rather than semantic.
It is true that the sentence "I need to deposit some money at the bank" is ambiguous, but its ambiguity is solely due to the semantic ambiguity of the word "bank." Since its ambiguity depends on the ambiguity of a single term, the sentence "I need to deposit some money at the bank" is not syntactically ambiguous. It is only semantically ambiguous.
An ad hominem argument is one in which the premises are about
the person making a point and the conclusion tells against their making that point.
Feedback:
The correct answer is A.
An ad hominem argument is one, whose premises are about the person or persons who make a certain point, and whose conclusion tells against that point. We saw that there were three kinds of ad hominem arguments: deniers, which state that the given conclusion is false; silencers, which state that someone has no right, or no permission, to make the given conclusion; and dismissers, which state that someone does not have the evidence or justification to make the given conclusion.
Which of the following arguments is an ad hominem?
Lying Larry told me that it will rain today, therefore, it probably will not rain today.
Feedback: The correct answer is B.
Because it begins with a premise about a person, and draws a conclusion that rejects that person's testimony, the argument in (b) is an ad hominem argument.
None of the arguments in (a), (c), and (d) are ad hominems, since none of them reject the conclusion of the person they mention. Finally, (e) is not an ad hominem because it does not conclude that Sam's testimony is false from Sam's screaming. (e) does not include the word "therefore," in other words.
An appeal to authority occurs when the premises are about
the person making a point and the conclusion tells in favor of their making that point.
The correct answer is B.
An appeal to authority is an argument, which supports an argument's conclusion on the basis of something about the person making the argument. We have seen three different kinds of arguments from authority: affirmers, which state that the given conclusion is true; amplifiers, which state that someone has a special right, or special permission, to make the given conclusion; and supporters, which state that someone does has particularly good evidence or justification to make the given conclusion.
Which of the following arguments is an appeal to authority?
Honest Abe told me that it will rain today, therefore, it will probably rain today.
Feedback: The correct answer is A.
Because it begins with a premise about a person, and draws a conclusion that supports that person's point, the argument in (a) is an argument from authority.
None of the arguments in (b), (c), (d), or (e) are arguments from authority, since none of them support the point of the person they mention.
A silencer is an argument in which the premises are about the person making a point, and the conclusion is that
they are not entitled to make that point in the context in which they did, so you should not listen to them.
Feedback: The correct answer is A. Silencer arguments are arguments, which state that a certain person does not have the right, or the permission, to offer the testimony that she offers
An amplifier is an argument in which the premises are about the person making a point, and the conclusion is that
they are especially entitled to make that point in the context in which they did, so you should pay special attention to them.
Feedback:
The correct answer is D.
An amplifier argument is one, which states that someone has a special right, or special permission, to make the argument that they are making. If one points to the fact that Ulrich is the assigned umpire for a baseball game, for instance, and if one also points out that assigned umpires have a special right to offer opinions about the game, then, by concluding that Ulrich's testimony is good, one makes an amplifier argument from Ulrich's authority.
A denier is an argument in which the premises are about the person making a point, and the conclusion is that
the point they are making is false.
Feedback:
The correct answer is C.
A denier argument is one, which begins with some observation about a person, and which concludes that the person's conclusion is false. A denier argument does not conclude that the person in question is unjustified, or that the person has no right to argue for her conclusion. A denier argument merely holds that a certain conclusion is false, and it does so on the basis of something about the person who draws that conclusion.
A dismisser is an argument in which the premises are about the person making a point, and the conclusion is that
they did not have enough evidence to make that point in the context in which they did, so you should not believe them.
Feedback:
The correct answer is B.
A dismisser argument begins with an observation about a person, and concludes that such a person is unjustified or unreliable in her arguments. It does not conclude that the person's conclusion is false, exactly. Nor does it conclude that the person has no right to argue. What it states is that, although there may be some chance that the person is right, the person is nonetheless unreliable or unjustified in what she argues.
A supporter is an argument in which the premises are about the person making a point, and the conclusion is that
they have more than enough evidence to make that point in the context in which they did, so you should be very confident that they are right.
The correct answer is E.
A supporter argument begins with a statement about a person, and concludes that the person has particularly good evidence for her argument, or is particularly reliable in her arguments. Supporter arguments do not simply say that a person's conclusion is true. Nor do they say that the person in question has a special right, or a special permission to argue. Rather, a supporter argument says that someone is particularly well-justified in making her argument. [Show Less]
