Just for fun I thought that I would post an essay that I recently submitted for a practical ethics course that I am doing on-line with Peter Singer, perhaps it will kick off some interesting discussion.
The goal of this essay is to describe and evaluate one argument against subjectivism in ethics. I’ll begin by suggesting a definition of subjectivism, and then I’ll proceed to outline one possible argument against subjectivism which could be seen as implicit in the remarks that Peter Singer made in the lectures (although he doesn’t actually go so far as to endorse this argument). Then I’ll offer reasons why we shouldn’t think that this argument gives us a decisive reason to reject subjectivism.
Let me propose the definition of subjectivism that I wish to work with. This definition is influenced by aspects of the slightly different definition given in the Wikipedia article on subjectivism, while also attempting to remain true to the spirit of what Peter Singer seemed to mean by “subjectivism” in the lectures. I propose that subjectivism means the view that, if there are ever any facts about reality which make a positive atomic moral judgement true, (a positive atomic moral judgement being one to the effect that a particular moral agent is under an obligation to perform a certain action), then it’s not the case that those facts are constitutively independent of human opinion.
Now I’ll outline one possible argument against subjectivism.
If subjectivism were the truth, then the practice of attempting to resolve ethical disagreements by reasoned argument would be irrational and would have no point to it.
But it’s not the case that the practice of attempting to resolve ethical disagreements by reasoned argument is irrational and has no point to it.
So subjectivism is not the truth.
This argument is deductively valid, but I want to argue that the second premise is at least open to question, and then I’ll go on to offer reasons for thinking that we should reject the first premise.
To begin with the second premise, this premise shouldn’t be regarded as being completely certain. The fact that the practice of attempting to resolve ethical disagreements by reasoned argument is quite widespread and generally believed to have some point to it shouldn’t be regarded as decisive evidence that the practice is in fact rational. It could be speculated that, as time goes on and widespread lack of theistic belief persists in our culture over a long period of time, this practice will eventually be abandoned and come to be seen as irrational. So the second premise should be regarded as being at least open to question.
However, what I would wish to urge and will now proceed to argue in more detail is that in fact the first premise should be rejected. I will define a version of subjectivism known as error theory, and then proceed to argue that even if error theory were the truth, there is at least a plausible account of moral discourse available on which the practice of attempting to resolve ethical disagreements by reasoned argument is fully rational.
Let me begin by stating the content of error theory about moral discourse. I define it to be the claim that, on those occasions when a speaker utters a positive atomic moral judgement in such a way that it has cognitive content, this utterance is always false. If one is to avoid making false statements and still continue to utter positive atomic moral judgements, one must take a non-cognitivist stance on what one is doing, which holds that one is merely expressing a personally held moral attitude towards a certain contemplated line of conduct rather than any actual beliefs about any aspect of reality. Due to limitations of space I cannot argue for this view, so I’ll just content myself with suggesting that it’s at least a plausible account of moral discourse.
I now want to suggest reasons why, even if error theory were the truth, nevertheless the practice of attempting to resolve ethical disagreements by reasoned argument could be fully rational.
Those people who continue to engage in normative ethical discourse and to attempt to resolve disagreements by means of reasoned argument despite having a non-cognitivist stance on what they are doing, are people who desire to have a set of moral attitudes which are as coherent, and unified, and as fully in harmony with the considerations that strike them as most intuitively compelling, as is possible. The desire to achieve such a set of moral attitudes and to have one’s behaviour governed by it is not irrational, and the practice of attempting to resolve ethical disagreements by means of reasoned argument is rational with respect to the fulfilment of this desire.
Since this is at least a plausible account of moral discourse and the rationality of the practice of attempting to resolve disputes by means of reasoned argument, we have on balance no good reason to accept the first premise of the argument against subjectivism which I outlined earlier. This first premise should be rejected, and on the whole this argument gives us no good reason to reject subjectivism. Subjectivism, and in particular error theory, should be considered a live option for what might be the truth about moral discourse.
Rupert, I have a number of comments on your essay, but let’s stat with this.
Your syllogism is sloppy.
Based on your definition above (which I didn’t accept) this statement is false.
Let’s not confuse premises with conclusions. Prior to stating #2. You have to show that it has a logical basis.
Circular reasoning.
Wait a minute. Why waste your time stating a syllogism that is invalid on its face, then attempt to disprove it?
I have no idea what the standard definition of error theory is, but your definition falsifies itself.
Occam
Rupert, I have a number of comments on your essay, but let's stat with this.
Your syllogism is sloppy.
1. Based on your definition above (which I didn’t accept) this statement is false.
2. Let’s not confuse premises with conclusions. Prior to stating #2. You have to show that it has a logical basis.
3. Circular reasoning.
Wait a minute. Why waste your time stating a syllogism that is invalid on its face, then attempt to disprove it?
I have no idea what the standard definition of error theory is, but your definition falsifies itself.
Occam
Well, suppose we start with your complaint about my definition of subjectivism, which definition would you prefer?
You missed my point. I wasn’t complaining about the definitions (that may come later). Rather, I was just saying the structure of your syllogism was fallacious.
And your definition of error theory seems to be internally inconsistent.
Occam
You missed my point. I wasn't complaining about the definitions (that may come later). Rather, I was just saying the structure of your syllogism was fallacious.
And your definition of error theory seems to be internally inconsistent.
Occam
Well, the logical form of the syllogism is
1. p implies q
2. not-q
3. therefore not-p
which is deductively valid in propositional logic. So where's the fallacy?
I'd also be interested to hear why the definition of error theory is internally inconsistent.
One problem, Rupert, may be that you are dealing with all the ideas at a high
abstraction level. As such, fallacies aren’t easily apparent. See the examples below.
Sorry, that is not a correct logical form. The main error is in the use of “implies".
That’s a probability term and doesn’t fit in deductive logic. To clarify this, write your
syllogism in the form of “if - then" and see if it makes sense to you. Second, set it
up structurally using a Venn diagram and see if it works.
Example using your structure:
P = dog growls
Q = vicious
Then according to your structure it would read::
dog growls implies vicious
not-vicious
therefore not dog growls
In the real world we know that non-vicious dogs will sometimes growl when
being playful. That is, #3 does NOT follow from the first two statements.
Quoting Rupert:
. . .error theory . . . the claim that, on those occasions when a speaker utters a positive atomic moral judgement in such a way that it has cognitive content, this utterance is always false.
My example: “Lois is an honest woman."
That statement is a moral judgement and it contains cognitive content.
I see no reason to declare it false.
Occam
One problem, Rupert, may be that you are dealing with all the ideas at a high
abstraction level. As such, fallacies aren't easily apparent. See the examples below.
===
Sorry, that is not a correct logical form. The main error is in the use of “implies".
That’s a probability term and doesn’t fit in deductive logic. To clarify this, write your
syllogism in the form of “if - then" and see if it makes sense to you. Second, set it
up structurally using a Venn diagram and see if it works.
Example using your structure:
P = dog growls
Q = vicious
Then according to your structure it would read::
1. dog growls implies vicious
2. not-vicious
3. therefore not dog growls
In the real world we know that non-vicious dogs will sometimes growl when
being playful. That is, #3 does NOT follow from the first two statements.
Quoting Rupert:
. . .error theory . . . the claim that, on those occasions when a speaker utters a positive atomic moral judgement in such a way that it has cognitive content, this utterance is always false.
My example: “Lois is an honest woman."
That statement is a moral judgement and it contains cognitive content.
I see no reason to declare it false.
Occam
Sorry, that is not a correct logical form. The main error is in the use of “implies".
That’s a probability term and doesn’t fit in deductive logic.
I would have to say that I feel like I'm in a position to correct you here. I'm extremely knowledgeable about mathematical logic, and I know that "implies" is one of the logical connectives of propositional logic, and that the logical form I gave is deductively valid in classical (and intuitionistic) propositional logic.
To clarify this, write your
syllogism in the form of “if - then" and see if it makes sense to you.
Sure, no problem.
1. If p then q
2. not-q
3. therefore not-p
Perfectly fine, you can verify the validity of the inference using the method of truth tables.
Second, set it
up structurally using a Venn diagram and see if it works.
Yeah, okay, so you draw two overlapping circles, and you shade in all the regions where the premises are true and the conclusion false, and you find that there are none, so it works. And?
Example using your structure:
P = dog growls
Q = vicious
Then according to your structure it would read::
1. dog growls implies vicious
2. not-vicious
3. therefore not dog growls
In the real world we know that non-vicious dogs will sometimes growl when
being playful.
Which means that premise (1) has some exceptions. So the argument is deductively valid, it's impossible that the premises could be true and the conclusion false, it's just that premise (1) is not true without exception.
That is, #3 does NOT follow from the first two statements.
It most certainly does.
My example: “Lois is an honest woman."
That statement is a moral judgement and it contains cognitive content.
I see no reason to declare it false.
All right, I grant you that's an interesting example. "Honest" is an example of a thick moral concept. My claim would be, that if you're using the term "honest" in a purely descriptive way, then the statement shouldn't be considered to be a moral judgement, and if you're using it in a way that it does have some normative content, then you should at least be open to the error theorist's claim that the statement is false, even if the descriptive part of it is true.
That is, #3 does NOT follow from the first two statements.
It most certainly does.
Is that your entire argument?
If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic.
However, here is an argument using truth tables.
We wish to show that the following inference is deductively valid.
1. if p then q
2. not-q
3. therefore not-p
Truth tables
p q if p then q not-q not-p
T T T F F
T F F T F
F T T F T
F F T T T
(I don't know how to get the columns to line up properly, but hopefully you can get the point.)
As we can see, none of the rows end in TTF. So the argument is valid.
That is one way to argue the point. Another way would be to demonstrate the validity of the inference using some accepted axiomatisation of classical or intuitionistic propositional logic.
However, anyone who has any doubts about the matter obviously just doesn't know propositional logic. To anyone with any knowledge of propositional logic, the point is completely trivial. So any attempt to argue the point is not likely to be very helpful.
When you offered counter-examples to the validity of the inference, you were describing situations where p is true and q is false. That means that premise (1) comes out false. So it's not a counter-example to the validity of the argument. For a counter-example to the validity of the argument you need a situation where the premises are true and the conclusion is false.
I didn’t provide the counterexample, but that is kinda the point for a “if p then q" premise isn’t it? By definition, you’re already theorizing about how the world works and a counterexample disproves your theory.
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Again you theorize that you are right and I am wrong. If that’s true, then you just need to school me. Either A) you’re doing a bad job of that or B) you’re not completely right. Either way, your statement comes across as extremely arrogant and serves only to shut down conversation, not enhance it.
Rupert is exactly right. The scheme of his argumentation is valid. However it is not a syllogism, but a perfect example of the modus tollens].
The confusion lies in the fuzzy wording of Occam’s example: ‘dog growls implies vicious’. Obviously it means ‘Sometimes when a dog growls’ it is vicious’. So it is not a rigid statement of the kind: ‘If a dog growls, then it is vicious’. From Occam’s further argument it is clear that he in fact means ‘If a dog is vicious, then it growls’. Then the opposite is not true: you cannot conclude from the dog growling that it is vicious, because there are also other reasons why it growls.
So, yes, Rupert’s argumentation schema is valid.
Being too succinct does not make things clear.
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Sorry Lausten, but if somebody would tell you 1 + 1 = 3, then you also would say that person knows no math. Rupert's argumentation schema is so fundamental to propositional logic, that in my opinion he has the right to be irritated. So let's de-escalate, and if you want, go the to contents of what Rupert wants to say in his essay.
Sorry that I have not taken yet the effort really to dive into it. Ethics is not my biggest interest in philosophy.
I didn’t provide the counterexample, but that is kinda the point for a “if p then q" premise isn’t it? By definition, you’re already theorizing about how the world works and a counterexample disproves your theory.
If you want to argue that premise (1) of the argument is false, then that's fine, I wasn't the one who came up with that premise anyway. That's different from trying to argue that the argument is not deductively valid. Do you know what "deductively valid" means? It means that it is logically impossible that the premises could be true and the conclusion false.
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Again you theorize that you are right and I am wrong. If that’s true, then you just need to school me. Either A) you’re doing a bad job of that or B) you’re not completely right. Either way, your statement comes across as extremely arrogant and serves only to shut down conversation, not enhance it.
Well, I've got a PhD in mathematics and three years full-time teaching experience, and when I give someone tutoring I'm usually getting paid. I'm not usually used to being told that I'm "doing a bad job" when I'm providing the service for free, or that I "need" to do it when I'm not getting paid any money. If I was actually getting paid, then of course negative feedback from the employer would be reasonable. I've been attempting to give you some tutoring for free, if you find it's not helping you then I'm sorry about that, but hey, it's a free service.
I would also note that you completely failed to engage with the part of my post where I made some attempt to show you the method of truth tables. It's not very helpful when a student tells me I'm doing a bad job of teaching them and refuses to engage with the lesson material in any way at all. If you could just in some way refer to what I actually said and tell me which bit you don't get, then maybe I can see if I can help you a bit more.
I'm very sorry you have the feeling that my statement comes across as arrogant. I don't see why that should be. What I said is factually accurate. Anyone with a basic knowledge of propositional logic would immediately recognise that what I said is correct. If you don't have that, then that's fine, there's no shame in that. As I say, I've been making some attempt to give you free tutoring, and I'm perfectly happy to do that, but it would be nice if you could acknowledge the offer of free tutoring as a gesture of goodwill, rather than complaining that I am being arrogant and "shutting down conversation".
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Sorry Lausten, but if somebody would tell you 1 + 1 = 3, then you also would say that person knows no math. Rupert's argumentation schema is so fundamental to propositional logic, that in my opinion he has the right to be irritated. So let's de-escalate, and if you want, go the to contents of what Rupert wants to say in his essay.
Sorry that I have not taken yet the effort really to dive into it. Ethics is not my biggest interest in philosophy.
In all honesty I'm not irritated, and also I'm really not trying to come across as arrogant, but I am speaking the truth when I say that if someone doesn't already get why the argument is deductively valid then it's a bit hard to know what to say. I would need to go through the basic concepts of propositional logic. I don't have any objection to doing that. I did make some preliminary efforts in the direction of making things clearer when I gave my argument based on truth tables. If Lausten could just engage with what I wrote there in some way then maybe we could succeed in communicating with one another.
I would also note that you completely failed to engage with the part of my post where I made some attempt to show you the method of truth tables. It's not very helpful when a student tells me I'm doing a bad job of teaching them and refuses to engage with the lesson material in any way at all. If you could just in some way refer to what I actually said and tell me which bit you don't get, then maybe I can see if I can help you a bit more.
I listed bad tutoring as one possibility. I can't know that for sure without someone of equal ability weighing in on this.
I did show you what i "don't get" when I said "but that is kinda the point for a “if p then q" premise isn’t it? By definition, you’re already theorizing about how the world works and a counterexample disproves your theory." I got that from here:
I would also note that you completely failed to engage with the part of my post where I made some attempt to show you the method of truth tables. It's not very helpful when a student tells me I'm doing a bad job of teaching them and refuses to engage with the lesson material in any way at all. If you could just in some way refer to what I actually said and tell me which bit you don't get, then maybe I can see if I can help you a bit more.
I listed bad tutoring as one possibility. I can't know that for sure without someone of equal ability weighing in on this.
I did show you what i "don't get" when I said "but that is kinda the point for a “if p then q" premise isn’t it? By definition, you’re already theorizing about how the world works and a counterexample disproves your theory." I got that from here:
I also "don't get" the part about your your truth table not resolving to TTF. But I think the above question is more important.
We are considering an argument of the following form:
(1) If p then q
(2) not-q
Therefore
(3) not-p
When we say that the argument is deductively valid, what we mean is that it is not logically possible that (1) and (2) could be true and (3) could be false.
You are arguing that (1) is in fact false. That is all well and good. But it is consistent with the argument being deductively valid. That does not contradict my claim. I never made any claim that (1) was true, it is just some random premise that Occam made up.
The reason why it is not logically possible that (1) and (2) could be true and (3) could be false is as follows.
There are four possible combinations of truth-values for p and q, corresponding to the rows of the following truth-table:
p q
T T
T F
F T
F F
We make the convention that every combination of truth-values makes "if p then q" true, except for p true and q false, which makes it false. So if we let (1) be "if p then q", (2) be "not-q", and (3) be "not-p", we end up with the following truth-table:
p q (1) (2) (3)
T T T F F
T F F T F
F T T F T
F F T T T
To find a counter-example to the validity of the argument, you need a row where (1) and (2) come out true and (3) comes out false, that is you need a row which ends in TTF. But there isn't any such row. Whenever (1) and (2) turn out true, it always happens that (3) turns out true as well. So the argument is deductively valid.
HTH.
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Sorry Lausten, but if somebody would tell you 1 + 1 = 3, then you also would say that person knows no math. Rupert's argumentation schema is so fundamental to propositional logic, that in my opinion he has the right to be irritated. So let's de-escalate, and if you want, go the to contents of what Rupert wants to say in his essay.
Sorry that I have not taken yet the effort really to dive into it. Ethics is not my biggest interest in philosophy.
But this isn't simple math and this isn't a university. Rupert's argument about getting paid is irrelevant. If you come to a general discussion and don't expect to have to explain something from your particular background, it seems like you're just here to show off. Would you lecture a 3 year old about getting 1 + 1 wrong?
I'm still not convinced he is using modus tollens correctly because his conclusion is "subjectivism is not the truth". That's too conclusive given the premises. He may add some subtlety later, but why didn't he just go back and rework the logic itself?
I don't see anything "escalating" about telling someone how I perceive their post, BTW. If I can't make an "I" statement, then what's the point in posting at all?
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Sorry Lausten, but if somebody would tell you 1 + 1 = 3, then you also would say that person knows no math. Rupert's argumentation schema is so fundamental to propositional logic, that in my opinion he has the right to be irritated. So let's de-escalate, and if you want, go the to contents of what Rupert wants to say in his essay.
Sorry that I have not taken yet the effort really to dive into it. Ethics is not my biggest interest in philosophy.
But this isn't simple math and this isn't a university. Rupert's argument about getting paid is irrelevant. If you come to a general discussion and don't expect to have to explain something from your particular background, it seems like you're just here to show off. Would you lecture a 3 year old about getting 1 + 1 wrong?
I'm still not convinced he is using modus tollens correctly because his conclusion is "subjectivism is not the truth". That's too conclusive given the premises. He may add some subtlety later, but why didn't he just go back and rework the logic itself?
I don't see anything "escalating" about telling someone how I perceive their post, BTW. If I can't make an "I" statement, then what's the point in posting at all?
But I have put a fair amount of effort into trying to explain, and so far you have completely ignored my explanations. And I did not "lecture" you. I simply correctly observed that if you can't see it then obviously the problem must be that you don't know any propositional logic, so that it would be necessary to start from scratch, and therefore arguing the point was likely to be a thankless task. As indeed it is proving to be.
I don't mind offering you free tutoring. And I don't even mind if I offer you free tutoring and you completely ignore what I say. I'd just prefer if you didn't then go on to say that the problem lies in me being a bad teacher.
I've taken the trouble to explain the method of truth tables to you. If there is some bit that you need more help with then I am happy to do what I can to try to help.
I don't know what your problem is with the deductive validity of the argument that I present in the essay. Maybe you can elaborate on what your reservations are.
Similar logic applies to your statement, “If any argument is necessary, that indicates that the person you are addressing has difficulty understanding propositional logic, so that any argument you offer is not likely to be helpful, and what is really needed is for the person to learn propositional logic."
Sorry Lausten, but if somebody would tell you 1 + 1 = 3, then you also would say that person knows no math. Rupert's argumentation schema is so fundamental to propositional logic, that in my opinion he has the right to be irritated. So let's de-escalate, and if you want, go the to contents of what Rupert wants to say in his essay.
Sorry that I have not taken yet the effort really to dive into it. Ethics is not my biggest interest in philosophy.
But this isn't simple math and this isn't a university. Rupert's argument about getting paid is irrelevant. If you come to a general discussion and don't expect to have to explain something from your particular background, it seems like you're just here to show off. Would you lecture a 3 year old about getting 1 + 1 wrong?
I'm still not convinced he is using modus tollens correctly because his conclusion is "subjectivism is not the truth". That's too conclusive given the premises. He may add some subtlety later, but why didn't he just go back and rework the logic itself?
I don't see anything "escalating" about telling someone how I perceive their post, BTW. If I can't make an "I" statement, then what's the point in posting at all?
But I have put a fair amount of effort into trying to explain, and so far you have completely ignored my explanations. And I did not "lecture" you. I simply correctly observed that if you can't see it then obviously the problem must be that you don't know any propositional logic, so that it would be necessary to start from scratch, and therefore arguing the point was likely to be a thankless task. As indeed it is proving to be.
I don't mind offering you free tutoring. And I don't even mind if I offer you free tutoring and you completely ignore what I say. I'd just prefer if you didn't then go on to say that the problem lies in me being a bad teacher.
I've taken the trouble to explain the method of truth tables to you. If there is some bit that you need more help with then I am happy to do what I can to try to help.
I don't know what your problem is with the deductive validity of the argument that I present in the essay. Maybe you can elaborate on what your reservations are.
I did what you asked in the initial response, then repeated it and gave you a link explaining why I had the question. I furthered explained my problem your conclusion in my last response. All you've done so far is explain that modus tollens is valid. You haven't shown that your use of it is correct. If I were you, I'd spend more time defending my original essay and adding clarity to it than dealing with the details of propositional logic.