Phil 2030: Introduction to Ethics
Dr. Robert Lane
August 29, 2014
[2.] Moral Reasoning.
[2.1.] Ethics and Inquiry.
ethics (df.): the area of philosophy that attempts to answer questions involving concepts such as right/wrong, good/bad, moral/immoral, etc. [In EMP ch.1, Rachels uses the phrase “moral philosophy” to refer to ethics.]
inquiry (df.): an attempt to discover truths about the world; research; investigation.
Ethics is not a matter of simply saying what you believe or feel about a given issue. It depends on reasoning and evidence. In ethics, we test existing theories, and develop new ones, primarily by reasoning. They give arguments to support their claims.
[2.2.] Arguments, Reasons, and the Minimum Conception of Morality.
An ethical claim is only as good as the arguments that one can give to support it. Because of this, most (but not all) philosophical work consists in arguing in support of philosophical claims.
In ethics, if you believe that something is right or wrong, you need to be able to back up that belief with good reasons. In other words, you have to be able to give an argument for your belief.
Suppose you say that in general, theft is immoral. If I ask you why you think this is the case, then you ought to be able to give me a reason, e.g., “It harms the person from whom something is being stolen.” This may be a good argument in support of the claim that, in general, theft is wrong. (A worse argument in support of that claim is: “Sometimes you end up stealing low quality goods and it’s really not worth the effort.”) If you can give no reason for asserting that theft is wrong, then I am within my rights to ignore you. This illustrates that morality is based on reasons.
This is much different than saying, e.g., “Turkey & Gravy flavored soda is delicious!” This is an acceptable statement, even if I have no reasons to give in support of them. In this way, moral claims are different than claims of personal preference.
This is a point that the author of EMP, James Rachels, emphasizes when he describes what he calls the Minimum Conception of Morality:
Morality is, at the very least, the effort to guide one’s conduct by reason—that is, to do what there are the best reasons for doing—while giving equal weight to the interests of each individual affected by one’s decision. (EMP 13)
This combines two ideas (EMP 10):
Rachels makes an important point about these three cases:
The cases of Baby Theresa, Jodie and Mary, and Tracy Latimer are liable to arouse strong feelings. Such feelings are often a sign of moral seriousness and may be admired. But they can also get in the way of discovering the truth: When we feel strongly about an issue, it is tempting to assume that we just know what the truth is, without even having to consider the arguments on the other side. Unfortunately, however, we cannot rely on our feelings, no matter how powerful they may be. Our feelings may be irrational; they may be nothing but the products of prejudice, selfishness, or cultural conditioning. At one time, for example, people’s feelings told them that members of other races were inferior and that slavery was God’s plan.
Moreover, people’s feelings can be very different. In the case of Tracy Latimer, some people feel very strongly that her father should have been given a long prison term, whereas others feel equally strongly that he should never have been prosecuted. But both of these feelings cannot be correct. (EMP 10-11, emphasis added)
Because people sometimes disagree about what is morally right, and because it is usually possible to give arguments for each side of a moral issue, we must be able to evaluate moral arguments. In other words, we must be able to tell good arguments about morality from bad ones.
To do this, we will need to take a detour out of ethics and into logic and consider some basic logical concepts. In particular, we need to understand:
[2.3.] Two Ways to Evaluate an Argument.
Consider this simple argument (from RTD 19):
(1) 1. All men are mortal.
2. Socrates is a man.
3. Therefore, Socrates is mortal.
There are two things about this argument that can make it a good argument or a bad argument:
First, does it have true premises or false premises? If all of the premises are true, then that is a good thing. If you are using an argument to try to convince someone that a claim (the argument’s conclusion) is true, you definitely want to cite reasons (premises) that are true. If an argument has one or more false premises, then it is a bad argument.
In argument (1), both premises are in fact true. All men (meaning, all human beings) are mortal. And Socrates is (was) in fact mortal.
But that is only one of two ways in which an argument can be good.
Second, does the conclusion follow from the premises? In other words, if the premises were true, would that guarantee that the conclusion is also true?
In argument (1), there is no way that the premises could be true and the conclusion false. So the truth of the premises would guarantee the truth of the conclusion.
An argument in which the truth of the premises would guarantee the truth of the conclusion is said to be valid:
validity (df.): A valid argument is one in which
1. the truth of the premises would guarantee the truth of the conclusion;
2. if the premises were true, then the conclusion would have to be true as well;
3. it is impossible for the premises to be all true and the conclusion to be false at the same time.
· These are three equivalent ways of defining validity.
· To say “the conclusion follows from the premises” is NOT an adequate definition of validity. To really explain what validity is, you must give at least one of the definitions cited above.
· IMPORTANT: In logic and philosophy, the word “valid” does not mean exactly the same thing that it does in ordinary English. For the purposes of this class, “valid” means only what it is defined to mean above: if the premises were true, then the conclusion would have to be true, as well. [Sometimes, this is called deductive validity.]
So argument (1) has all true premises and it is valid. Here is another argument that has all true premises and is valid:
(A) 1. All mammals are animals.
2. All dogs are mammals.
3. Therefore, all dogs are animals.
[2.4.] Valid Arguments with False Premises.
Another example of a valid argument (RTD 20)
(2) 1. All people from Georgia are famous.
2. Jimmy Carter is from Georgia.
3. Therefore, Jimmy Carter is famous.
Despite the fact that this argument has a false premise, it still valid: if the premises were all true, then the conclusion would have to be true as well.
In other words, it is valid. The same is true of this argument:
(B) 1. All US Presidents are from Chicago.
2. Barack Obama is a US President.
3. Therefore, Barack Obama is from Chicago.
In summary: the validity of an argument does not depend on whether the premises are actually true or false. So far as validity is concerned, it does not matter whether all of the premises are actually true, some of them are actually true, or none of them is actually true.
When you think about whether an argument is valid, do not ask whether the premises are actually true or false. Instead, ask: if the premises were true, would the conclusion then have to be true, as well?
It is important to define validity this way:
1. if the premises were true, then the conclusion would have to be true as well.
2. the truth of the premises would guarantee the truth of the conclusion
…instead of this way:
(*) if the premises are true, then the conclusion must be true as well;
the truth of the premises guarantees the truth of the conclusion.
(*) is not a good definition of validity, because it implies that the premises must actually be true in order for the argument to be valid. But that’s wrong: the premises do not actually have to be true in order for the argument to be valid.
[2.5.] Invalid Arguments.
Here are some examples of arguments that are not valid…
C. 1. Atlanta is located in Georgia.
2. The moon orbits the earth.
3. Therefore, Barack Obama is President.
Both premises are true, but this in no way indicates that the conclusion is true.
Here is another argument that is not valid, even though it has premises that are all true, and even though its premises are talking about the same subjects:
D. 1. Some US Presidents are from Georgia.
2. Barack Obama is a President.
3. Therefore, Barack Obama is from Georgia.
Arguments that are not valid are invalid:
invalidity (df.): An invalid argument is one in which the truth of the premises would not guarantee the truth of the conclusion. I.e. (in other words) it is possible for the premises to be true and the conclusion false at the same time.
When we critically evaluate an argument, we will be asking two related questions:
b. Are all of the premises true?
b. Is it valid?
If the answer to both questions is “yes,” then the argument is said to be sound.
soundness (df.): A sound argument is an argument that (1) has all true premises AND (2) is valid.
But if the answer to either question is “no,” then the argument is not sound, and we should reject it.
The fact that an argument is not sound does not mean that its conclusion is false. All that can be concluded from the fact that an argument is unsound is that the conclusion has not been proved true by that argument, and a different argument is needed to support the conclusion. This is illustrated by this argument:
C. 1. Atlanta is located in Georgia.
2. The moon orbits the earth.
3. Therefore, Barack Obama is President.
[This argument has a true conclusion. But it is unsound because it is invalid. (It does have two true premises, but it is nonetheless unsound.)]
as well as by this argument:
E. 1. Beyonce is a nuclear engineer.
2. All nuclear engineers are famous.
3. So, Beyonce is famous.
[This argument has a true conclusion. But it is unsound because it has false premises. (It is valid, but it is nonetheless unsound.)]
There are some arguments that are good in their logical aspect, even though they are not valid. These are sometimes called inductive arguments.
· In these arguments, the truth of the premises would provide a very good reason for thinking the conclusion is true, but would not guarantee the truth of the conclusion. For the most part, we will not be discussing those types of arguments in this class.
· The majority of the arguments we discuss in this class will be either valid or logically bad. To learn about these other types of arguments, you can take the Philosophy Program’s Critical Thinking course (PHIL 2020; 3 hrs credit in core area B1).
Stopping point for Friday August 29. For next time:
· study today’s lecture notes;
· continue reading RTD chapter 2: pp.21-24 only (up until the beginning of the section called “The Provability Argument”).
You may have a pop quiz over all of this material (today’s lecture notes and the assigned reading) at the beginning of the next class. Also, if you have not already done so already, read the syllabus thoroughly.
 Unfortunately, this is a real thing. See http://content.time.com/time/specials/packages/article/0,28804,1913612_1913610_1913571,00.html , accessed August 24, 2014.
 Like the arguments about Baby Theresa, Argument 1 and Argument A are displayed in a way that makes it very explicit which statements are the premises and which is the conclusion. But most of the time, when you come across an argument in your reading (even in your philosophy reading), it will not be indented from the margin, with each statement on a separate line. Normally, it will be written in prose form. Further, the conclusion may come before the premises. For example, Argument A could be written: “Of course dogs are animals; they’re mammals, and all mammals are animals.”