The next argument Rachels considers is an argument in support of full-blown moral skepticism. In other words, it is an argument in support of moral skepticism about everything, not just about a single issue (like infanticide, abortion, capital punishment, etc.). If full-blown moral skepticism is true, then no action whatsoever is objectively wrong ... not even rape, or killing innocent people for fun.
This argument is at RTD p.25:
Remember the definition of “objective”: something is objective when it is the way it is whether or not anyone thinks, or feels, or believes that it is that way.
So this argument is trying to convince us that there is no fact of the matter – no “objective truth” – about whether any action is right or wrong. In other words, this is an argument for full-blown moral skepticism.
[2.8.1.] Valid or Invalid?
1. If it were true that p, it would also be true that q.
2. But it is not true that q. [This premise denies the q portion of the first premise.]
3. Therefore, it is not true that p.
And any argument that has this form is valid. It does not matter what propositions you fill in for “p” and “q”; so long as both “p”s are replaced with the same proposition and both “q”s are replaced with the same proposition, the resulting argument will be valid. For example,
1. If Atlanta is the capital of Georgia, then the moon is made of cheese.
2. The moon is not made of cheese.
3. Therefore, Atlanta is not the capital of Georgia.
This is a valid argument, even though one of its premises is false.
· that a test was unfair
· that “Jones is a bad man”
· that “Dr. Smith is irresponsible”
· that “A certain used-car salesman is unethical.”
We can prove that a test is unfair by showing that it has nothing to do with the class content, is too long for any student to finish, that it does not follow the study guide that the professor provided for the test, etc. And we can prove that Jones is a bad person by showing that he is a habitual liar, that he abuses his wife and children, that he tortures puppies for fun, and so on.
Discussion: is Rachels right to say that we can prove these claims to be true? Is there are difference between proving a moral claim and simply providing good reasons to believe it.
Stopping point for Monday September 8. For next time, study the lecture notes from today, and read EMP ch.2, sections 2.1 and 2.2. You may have a pop quiz on both at the beginning of class.
This page last updated 9/8/2014.
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