P6 Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted.* — Soylent

I take issue with this. I don't think free range husbandry followed by the swift killing of animals would constitute gratuitous suffering. Therefore any gratuitous suffering caused by food production practices is preventable by changing those food production practices to free range husbandry followed by the swift killing of animals – which is consistent with a meat-eating diet.

Why is it okay to kill an animal but not a human?

I would take issue with that premise as well. I've denoted questionable premises with an (*). They're not necessarily bad premises, but require a lot of support.

I didn't say that it's OK to kill an animal but not a human.

I don't think free range husbandry followed by the swift killing of animals would constitute gratuitous suffering. — Michael

I understand this to mean that you believe that killing an animal does not violate morality. (pointing out the difference between suffering and gratuitous suffering instead of saying killing animals is wrong)

Why would you think I meant that? I certainly didn't say anything to that effect. I simply addressed the claim that "[g]ratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted". I only said that gratuitous suffering can be prevented without adopting a vegan diet.

My mistake. Guess I'm just trigger happy for an argument.

@MIchael @darthbarracuda From the OP: "If there is an interest to discuss the soundness of the premises, I can create a spinoff thread elsewhere."

The first thing to note is that C3 does not actually use P6 (also, your current P7 isn't completely independent since it follows from P6). That's good news because it means you don't have to worry about it when wording P7 and P8. Therefore, you can change them to:

P7 If it is possible to adopt and maintain a vegan diet, then gratuitous suffering caused by food production practices is preventable
P8 It is possible to adopt and maintain a vegan diet.

And these two together get you C3.

Essentially, C3 says that the gratuitous suffering caused by food production practices is preventable, while P6 says that veganism is the only way to prevent the gratuitous suffering caused by food production practices.

(P.S. If you are trying to patch up this argument, you're going to have to address the slide from "some non-human animals" to "all non-human animals" that is implicit in adopting veganism. Also, are you interested in shorter and/or simplified versions of the argument?)

If suffering is inherent in all compounded beings, you can't devise a plan to eliminate suffering.

Perhaps you could take an approach which is based on preserving a diversity of animals rather than preventing animal suffering but would still conclude with veganism. You can arrange it in P/C form, but...

IF human activity is destroying the basis for diverse life on earth--including human life--(global warming) we should adopt sustainable patterns of life.
Using animals for food production contributes to unsustainable patterns of life by aggravating global warming.
A vegan diet would be a more sustainable than a diet containing meat.
Therefore, we should switch to a vegan diet.

A vegan diet would improve life for humans and animals alike by making life more sustainable and maintaining a diversity of life.

This will eliminate our involvement in gratuitous suffering from animal husbandry and fishing. (It will increase my suffering, because I like meat, but we all have to make sacrifices for the greater good.)

P7 If it is possible to adopt and maintain a vegan diet, then gratuitous suffering caused by food production practices is preventable
P8 It is possible to adopt and maintain a vegan diet. — Postmodern Beatnik

Yes! I like this proposal. Thank you!

I said C3 follows from P6, P7, and P8 because P7 is an elimination of the biconditional. The biconditional adds a robustness in the ought claim, if it can be maintained with a defense of the soundness.

Also, are you interested in shorter and/or simplified versions of the argument? — Postmodern Beatnik

This is a simplified version where other versions I've drawn up offer additional conditional claims for the moral claim of eliminating gratuitous suffering (e.g., a reasonable cost condition). I thought for the sake of analysis of the formal aspect of the argument, the simple argument was the best so people don't get wrapped up in the content of the premises.

*edited*

From the OP: "If there is an interest to discuss the soundness of the premises, I can create a spinoff thread elsewhere." — Postmodern Beatnik

Right. I was being a trigger happy, argumentative ass.

Hey @Soylent, I think the changes recommended by @Postmodern Beatnik are an improvement to P7 & P8 but there is still something wrong with them, they, including P6 don't have a subject.

P6 Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted.

Adopted by whom? The obvious answer 'if it's adopted by everyone' is problematic as then P8 would need to be a strong statement 'it is possible for everyone' something that you probably don't want the argument to hinge on.

In a formal assessment, the ambiguity of the subject is not a problem unless explicit reference dispels the possibility of equivocation by the reader. I would address that issue as a preface to the argument explaining the purpose of the ambiguity and cautioning the reader that the subject is ripe for equivocation but the ambiguity is indeed purposeful (which I will explain in the other thread, time permitting).

For the sake of discussion, do you have any suggestions to solve the problem you brought up, or do you think it's beyond repair?

I said C3 follows from P6, P7, and P8 because P7 is an elimination of the biconditional. The biconditional adds a robustness in the ought claim, if it can be maintained with a defense of the soundness. — Soylent

Sure. But the standard way of writing that would be to identify P7 as following from P6 (which would make P7 C3), and then C3 (which would now be C4) would be listed as following from P7/C3 and P8. Right now, you have P7 listed as if it is just another assumed premise. It's just a minor technicality. And since it turns out you don't need the original P7, it doesn't end up causing any real problems.

This is a simplified version — Soylent

Fair enough!

Right. I was being a trigger happy, argumentative ass. — darthbarracuda

No problem. I was being a hypercorrective ass. ;)

Adopted by whom? — shmik

By anyone who is in a position to, I would think. There are two ways to go about this: rewording the argument to make it explicitly apply only to those who are in a position to adopt a vegan diet, or to leave it as is and accept that it is only applicable to those who are in a position to adopt a vegan diet. Moreover, I do not think that "adopted by all" is the natural reading here in part because the elimination of all suffering cannot possibly be the goal here. In fact, considering this might lead us to think that the "by those who are in a position to" condition is already built into the argument: it may not count as known and preventable gratuitous suffering if one is not in a position to avoid inflicting it.

For the sake of discussion, do you have any suggestions to solve the problem you brought up, or do you think it's beyond repair? — Soylent

By anyone who is in a position to, I would think. There are two ways to go about this: rewording the argument to make it explicitly apply only to those who are in a position to adopt a vegan diet, or to leave it as is and accept that it is only applicable to those who are in a position to adopt a vegan diet. Moreover, I do not think that "adopted by all" is the natural reading here in part because the elimination of all suffering cannot possibly be the goal here. In fact, considering this might lead us to think that the "by those who are in a position to" condition is already built into the argument: it may not count as known and preventable gratuitous suffering if one is not in a position to avoid inflicting it. — Postmodern Beatnik

The problem is that P6 is not necessarily true depending on the subject. As far as I can tell it comes closest to being true when everyone adopts a vegan diet. There is no direct link between the person who eats the animal and the treatment of the animal. It could well be that my going vegan does not have any effect on the animals that are farmed, chances are my super market is not going to order less meat because I am no longer buying from them.
That would be something that needs to be addressed before P6 can be assumed unless P6 does mean 'by everyone'. One method to go about this that I have seen is to say that there is a small chance of your particular purchase effecting the super market purchasing, but if it is the one then it will cause a large change in the purchasing i.e. if a supermarket buys chicken in lots of 1000 kg then your 1kg will almost certainly not cause the supermarket to by an extra 1000, but it might. Relying on an argument like that would loosen the argument in the OP.

There is no direct link between the person who eats the animal and the treatment of the animal. — shmik

That depends on the person. Not everyone gets their food from a supermarket or a restaurant.

It could well be that my going vegan does not have any effect on the animals that are farmed, chances are my super market is not going to order less meat because I am no longer buying from them. — shmik

But the choice is not between reading P6 as meaning "by everyone" or "just by one person." If the reading is "by anyone who is in a position to," as I suggested, that is going to be a very large number of people. So the fact that you cannot change your local supermarket's buying patterns alone is irrelevant. And if it were true that a vegan diet ought to be adopted by anyone who is in a position to do so, then it wouldn't matter whether or not other people will in fact do so. All that would matter is whether or not any given individual was in a position to adopt a vegan diet.

(The argument could also be rearranged to be more explicitly about participating in the production of gratuitous suffering. But that would get us into issues of deontology vs. consequentialism.)

That depends on the person. Not everyone gets their food from a supermarket or a restaurant. — Postmodern Beatnik

Which is my point, it depends on the subject.

But the choice is not between reading P6 as meaning "by everyone" or "just by one person." If the reading is "by anyone who is in a position to," as I suggested, that is going to be a very large number of people. So the fact that you cannot change your local supermarket's buying patterns alone is irrelevant. And if it were true that a vegan diet ought to be adopted by anyone who is in a position to do so, then it wouldn't matter whether or not other people will in fact do so. All that would matter is whether or not any given individual was in a position to adopt a vegan diet. — Postmodern Beatnik

I disagree that this follows from the premises. I think it very much does matter what whether or not other people adopt a vegan diet. We are claiming in 6 that if every element of the set of people who can go vegan, do go vegan, then we will achieve a desired outcome. This speaks about one specific situation and says nothing about the outcome of any other distribution of veganism within the set. Effectively we have a statement like: if X&Y&Z then T. Nothing is said about X&Y&~Z.

So with P9 and C5 all we can say is that the set of people who can go vegan should go vegan (as a set). The argument can almost never claim that any individual should go vegan. The only claim the argument could legitimately make is that if everyone else who could go vegan, did go vegan then I should participate in it. Otherwise there is a slide from then group as a whole to individuals which cannot be justified without extra premises.
As an example: if it were the case that my going vegan now increased the suffering of animals, the argument would be unaffected.

For clarity, you are addressing the soundness of P6 on the grounds that if other people (or most people) do not also adopt a vegan diet, then the actions of an individual in adopting a vegan diet cannot be said to prevent gratuitous suffering. Moral arguments are meant to be applied by the individual but hold for the entire group of moral agents. If the argument holds, the individual has a responsibility to prevent gratuitous suffering by the individual's and only individual's actions, but the argument holds irrespective of the particular subject. This is not an obligation to adopt a vegan diet if and only if everyone else also adopts a vegan diet. The collective consequence of the argument should be a wholesale adoption of a vegan diet and the sort of effect on gratuitous suffering in general that you seem to be imagining. However, the scope of the argument is limited such that regardless of whether others adopt a vegan diet as well (even though the argument applies to them), the reader has a moral responsibility to adopt a vegan diet. I regard your rebuttal as a sort of tragedy of the commons justification, whereby an individual can excuse their own immoral behaviour so long as everyone else is also acting immorally.

Not quite, I'm saying that if P6 refers strictly to an individual then I think it is unsound. This is because each individual does not necessarily play a contributory role in causing suffering. If we can agree that there exist one individual whose decision to become vegan would not effect the amount of animal suffering, then the if and only if is false.

My other issue is the formal one about the argument. If as Postmodern Beatnik suggests P6 is the set of all people for whom its possible to go vegan, then you cannot conclude that any individual ought go vegan.
Looking at it closer the problem is with P9.

P9 If it is wrong to allow gratuitous suffering caused by food production practices, and gratuitous suffering caused by food productions practices is preventable if and only if a vegan diet is adopted, then a vegan diet ought to be adopted. — Soylent

If P6 refers to a set, then P9 should be:
P9 If it is wrong to allow gratuitous suffering caused by food production practices, and gratuitous suffering caused by food productions practices is preventable if and only if a vegan diet is adopted (by the set referred to in P6), then one ought to ensure that a vegan diet is adopted by the set referred to in P6.

There is no justification in any of the argument which would allow us to conclude in P9 that one ought to ensure that a vegan diet is adopted by a subset of the set described in P6.

Edit: Both of these objections apply before the ought is encountered in the argument. It's not tragedy of the commons if I object to P6 by saying that it is false if it is referring to a single subject, or that the argument is invalid if P6 refers to a set of subjects. Are you making the claim that P6 is sound for an individual subject?

Which is my point, it depends on the subject. — shmik

Whether there is a direct link depends on the subject. But you have yet to show why a direct link matters to the validity of the argument.

I disagree that this follows from the premises. — shmik

It's unclear what you think doesn't follow. The point I was making was very simple: "some" follows from "all." So if the argument succeeds in getting "anyone who is in a position to adopt veganism ought to do so," it can get "S, an individual who is in a position to adopt veganism, ought to do so" as well. It's the same way that you don't get to murder someone just because you live in a place where someone else will do it if you don't.

I think it very much does matter what whether or not other people adopt a vegan diet. — shmik

But that's going to depend on the nature of the wrong. I mentioned before that the argument could be rewritten depending on whether one is addressing deontologists or consequentialists. For instance, P1 could just as easily be "If any gratuitous suffering is preventable and known, it is wrong to participate in said gratuitous suffering" (and mutatis mutandis throughout).

Even on the consequentialist reading, though, I don't think one gets to opt out just because one's effect is minimal. At best, you have shown only that vegans have duties beyond merely abstaining from the use of animal products. They might have to write to their grocer, discuss the issue with other people, and so forth. But it seems a mistake to judge the impact of an individual person's abstinence solely in terms of the short term effect on a local supermarket's bottom line. If consequentialists only looked at the short term, they'd never go to the dentist either. But that's clearly a straw man version of consequentialism.

We are claiming in 6 that if every element of the set of people who can go vegan, do go vegan, then we will achieve a desired outcome. This speaks about one specific situation and says nothing about the outcome of any other distribution of veganism within the set. Effectively we have a statement like: if X&Y&Z then T. Nothing is said about X&Y&~Z. — shmik

Sure. But the biconditional is not the end of the story. It's a premise, and all that matters for the topic of this conversation is whether or not it does its job as a premise. Strictly speaking, worrying about whether or not it is true is a topic for the associated discussion. Nor does it matter that nothing is said about (X & Y & ¬Z). The point of P6 is just to be part of the antecedent in P9 (and, originally, to get us P7).

So with P9 and C5 all we can say is that the set of people who can go vegan should go vegan (as a set). The argument can almost never claim that any individual should go vegan. — shmik

But again, "some" follows from "all." If all x ought to P, then x1 ought to P.

P9 If it is wrong to allow gratuitous suffering caused by food production practices, and gratuitous suffering caused by food productions practices is preventable if and only if a vegan diet is adopted (by [ oneself as a member in ] the set referred to in P6), then one ought to ensure that a vegan diet is adopted by [ oneself as a member in ] the set referred to in P6. — shmik

What about this amendment (and subsequent amendments to premises and conclusions to include this amendment)? It doesn't address the soundness of P6, but it makes the individual obligation explicit and not dependent on the entire set adopting veganism. It might weaken the soundness claim of P6, but that's a topic for elsewhere.

I find this amendment addresses a rather pedantic and uncharitable reading where you seem to be looking for a "technical" out by feigning ignorance of whom the argument is referring.

This is because each individual does not necessarily play a contributory role in causing suffering. — shmik

This takes a degree of special pleading and denial about one's actions to hold as justification for eating meat. In essence, it seems to argue that because the amount of suffering caused or alleviated by an individual's actions is miniscule and negligible, the individual can carry on with the immoral behaviour.

Hey Soylent I think you are getting me wrong here. I am not invested in the argument and have myself been vegan for some years of my life. I like the technical aspects of arguments which is why I am writing.

The problem with P6 is about thresholding. Repeating from my earlier post. There is a high chance that any individual purchase of meat I make from a supermarket will have literally zero effect. This is because in order for my purchase or lack of purchase to have an effect the supermarket must realize that it needs more or less meat. If they are selling 1000 kg a day, they won't even notice that I have stopped purchasing, therefore they won't change their order from the butcher and the butcher won't purchase less from the farm etc. We can think of this in thresholds, lets say the supermarket us purchasing an order of 7000kg per week. If they sell more than 6500kg of that then the next week they purchase 8000kg, if they sell less than 6500 then the next week they purchase only 6000kg. In this system, in order to make a difference to the animals your steak dinner must be the one that causes the supermarket to surpass the 6500kg mark.

We can treat this by introducing probability, by saying something like there is a very small chance that your small purchase will cause the supermarket to exceed it's threshold, but if it does cause that then it will be responsible for the super market making a very large extra purchase of meat.

P6 does not work for an individual without something like this.

I honestly do believe that the subject of the argument is significant, if it was referring to everyone then there would be no issue with thresholding. But then, as I mentioned P8 may end up being too strict for your taste.

There is some ambiguity in the terms. Maybe you could rewrite P6 in a way that incorporated your 'by anyone who is in a position to'.
'Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to', specifically excludes some (only if). If you mean it in the way: let X be the set of anyone who can go vegan, and V the set of vegans, ∀ x ∈ X, gratuitous suffering is preventable iff x ∈ V. Then that isn't true if there is a single individual whose capable of becoming vegan but whose contribution does not have an effect, which was the original concern.

Sure. But the biconditional is not the end of the story. It's a premise, and all that matters for the topic of this conversation is whether or not it does its job as a premise. Strictly speaking, worrying about whether or not it is true is a topic for the associated discussion. Nor does it matter that nothing is said about (X & Y & ¬Z). The point of P6 is just to be part of the antecedent in P9 (and, originally, to get us P7).

So with P9 and C5 all we can say is that the set of people who can go vegan should go vegan (as a set). The argument can almost never claim that any individual should go vegan. — shmik

But again, "some" follows from "all." If all x ought to P, then x1 ought to P. — Postmodern Beatnik

I agree that some follows from all generally.

Essentially this is what I see as happening here. Let's take a situation where Brian has 21 friends and soccer is 'the good'.
I can say 'Brian you ought to go to the park to play soccer'. To which Brian replies that no one is in the park and he needs another 21 people to play the game. He claims that the good is not achieved unless there are 22 people in the park to playing soccer. I then reply, 'Brian you ought to go to the park and all your friends ought to go with you'.
Now with some trick we can say Brian ought to go to the park, even though none of his friends are there and the situation is unchanged.

That's the same move I see happening, you require the group in order for P6, then switch back to the individual in P9. But P9 is only justified if it is fulfilled by the group as per P6.

I agree that some follows from all generally. — shmik

Great. But in fact, "some" always follows from "all." To say that something is true of all members of a set is to say that it is true of each member. Therefore, it must be true of some members of the set (which is to say that it must be true of at least one member of the set).

I then reply, 'Brian you ought to go to the park and all your friends ought to go with you'. — shmik

And if you said this, you'd be wrong. Brian ought to go to the park (if and) only if 21 of his other friends are going and they are willing to play soccer (with him). What you might suggest to Brian, then, is that he bring 21 friends with him to the park. Furthermore, this is not the same move if my previous point (that the short term impact on a local supermarket is not the proper measure of whether someone is in a position to reduce the gratuitous suffering of food animals) is correct.

But again, the purpose of this discussion is to investigate the validity of the argument, not the truth of any given premise. Here is the current version of the argument in propositional calculus:

Let:
A = some gratuitous suffering is preventable
B = some gratuitous suffering is known
C = it is wrong for someone in a position to prevent gratuitous suffering to allow it
D = some nonhuman animals are sentient
E = food production practices would constitute gratuitous suffering in humans
G = food production practices constitute gratuitous suffering in non-human animals
H = it is possible to adopt a vegan diet
I = a vegan diet ought to be adopted by all who are in a position to adopt it

Argument:
P1. (A & B) --> C
P2. (D & E) --> G
P3. D
P4. E
C1. G
P5. G --> B
C2. B
P6. A <=> H
P7. H --> A
P8. H
C3. A
C4. C
P9. (C & (A <=> H)) --> I
C5. I

As far as I can tell, this is a valid argument. Therefore, it seems to me your objections must be about the truth of the premises (which is a subject for the other discussion). I agree that P6 is false. I just disagree that its falsity has anything to do with whether or not the argument is valid.

I'm pretty sure that this is all because of a ambiguity in P6 as I mentioned above.
There are 2 interpretations.
1) Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who can adopt it.

2) For each individual who can go vegan, their contribution to gratuitous suffering caused by food production practices is preventable if and only if they adopt veganism.

I initially though that you meant 1, which has the analogue of the soccer argument. This is because the bi-conditional here means that the entire group needs to adopt veganism for the gratuitous suffering to be preventable.
If you meant 2 then I agree there is no problem going from all to some and the argument is fine (besides for the many premises I disagree with).

Can we agree to that? Do you see where I have been coming from?
One reason I wanted clarity in the first place is that I think the argument can easily sneak in logic such as: if everyone does X it will be good, therefore everyone should do X, therefore each individual should do X regardless of what others do. I'm guessing we agree that this would be invalid we just disagreed about whether it was happening (because of different readings of P6).

There are 2 interpretations. — shmik

But when there are two interpretations and one of them has no problems, you assume the one with no problems is the one that was intended. It's called the principle of charity.

Also, I don't think you have formulated the first option correctly. What you've written is the ambiguous formulation itself. Your (1) should be: "Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is simultaneously adopted by everyone who can adopt it." But of course, it is obvious that this is not what the argument intends to assert once this interpretation is made explicit. So while I can agree that this interpretation would cause problems, I don't see any reason to read it into the argument.

P6 Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted — Soylent

But when there are two interpretations and one of them has no problems, you assume the one with no problems is the one that was intended. It's called the principle of charity. — Postmodern Beatnik

Interesting that you frame the discussion like this considering my first and second posts state that there is an ambiguity, assume that interpretation (2) is the one that Soylent means and suggest a way to patch up the argument so that interpretation (2) works.

It's true that in my conversation with you I have taken (1) as your interpretation but this is the most charitable interpretation (of your posts).

But the choice is not between reading P6 as meaning "by everyone" or "just by one person." If the reading is "by anyone who is in a position to," as I suggested, that is going to be a very large number of people. So the fact that you cannot change your local supermarket's buying patterns alone is irrelevant. And if it were true that a vegan diet ought to be adopted by anyone who is in a position to do so, then it wouldn't matter whether or not other people will in fact do so. All that would matter is whether or not any given individual was in a position to adopt a vegan diet. — Postmodern Beatnik

This is clearly false under interpretation (2) being that interpretation (2) is false if there is one person whose independently going vegan has no effect. As such instead interpretation (1) is the charitable one. If you can find a way to make this quote work for interpretation (2) I'm happy to hear it.

Also, I don't think you have formulated the first option correctly. What you've written is the ambiguous formulation itself. Your (1) should be: "Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is simultaneously adopted by everyone who can adopt it." But of course, it is obvious that this is not what the argument intends to assert once this interpretation is made explicit. So while I can agree that this interpretation would cause problems, I don't see any reason to read it into the argument. — Postmodern Beatnik

The way I have written it is unambiguous, the only thing that could be ambiguous is the timing of each persons adoption.

Interesting that you frame the discussion like this considering my first and second posts state that there is an ambiguity, assume that interpretation (2) is the one that Soylent means and suggest a way to patch up the argument so that interpretation (2) works. — shmik

You seem to be confused. All I was saying with the point about charity is that the one interpretation is obviously not what was intended that there's no real threat to the argument's validity. The first interpretation is not relied on anywhere else in the argument, so there is no reason to read an equivocation into the argument.

It's true that in my conversation with you I have taken (1) as your interpretation but this is the most charitable interpretation (of your posts). — shmik

Then you are definitely confused because I haven't endorsed (1) or (2). Your argument only works if we are taking P6 to be "gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to do so" (which is the original version of P6 with my suggestion about who is involved tacked on). But from the beginning, I have been suggesting an alternative P6 (along with an alternative P7 and P8): "gratuitous suffering caused by food production practices is preventable if and only if it is possible to adopt a vegan diet." This alteration already incorporates the "anyone who is in a position to" suggestion in virtue of adding a modal term to the claim.

(I have also suggested that "contribution" should be interpreted broadly such that it involves more than a short-term decrease in the amount of suffering that exists. The one giving the argument could then claim that there is not one person for whom going vegan would have no effect. We might wonder about the truth of such a claim, but this thread is about the argument's validity.)

The way I have written it is unambiguous. — shmik

Then you seem to be contradicting yourself. Your original complaint was that the original version of P6 is ambiguous. You then claimed that P6 with the "anyone who is in a position to" clause tacked on is also ambiguous. But P6 with the "anyone who is in a position to" clause tacked on gets us "gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to do so." If this is ambiguous—and your entire argument is based on the claim that it is—then "gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who can adopt it" is also ambiguous (as it is essentially the same claim).

You seem to be confused. All I was saying with the point about charity is that the one interpretation is obviously not what was intended that there's no real threat to the argument's validity. — Postmodern Beatnik

OK, maybe you don't realize that its unpleasant when someone implies that your posts rely on uncharitable interpretations and that it comes across condescending when you then post a link to the principle of charity.

Then you are definitely confused because I haven't endorsed (1)
or (2). — Postmodern Beatnik

OK for now this part doesn't really matter as we have been talking past each other. We could argue about how legitimate my belief was that you were using one interpretation instead of another but it's pretty pointless.

Then you seem to be contradicting yourself. Your original complaint was that the original version of P6 is ambiguous. You then claimed that P6 with the "anyone who is in a position to" clause tacked on is also ambiguous. But P6 with the "anyone who is in a position to" clause tacked on gets us "gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to do so." If this is ambiguous—and your entire argument is based on the claim that it is—then "gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who can adopt it" is also ambiguous (as it is essentially the same claim). — Postmodern Beatnik

Maybe I have somewhere, who knows?
P6. gratuitous suffering caused by food production practices is preventable if and only if it is possible to adopt a vegan diet. Is ambiguous. Writing that this applies to anyone who is in a position to do so is also ambiguous.

P6. gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to do so. Is unambiguous, it means that gratuitous suffering... iff everyone who can go vegan does go vegan. The fact that you implied that you were endorsing a P6 with 'anyone who is in a position to do so' tacked on was one of the main reasons I thought you were using the interpretation that implied that collective action was necessary. I actually addressed this point in:

There is some ambiguity in the terms. Maybe you could rewrite P6 in a way that incorporated your 'by anyone who is in a position to'.
'Gratuitous suffering caused by food production practices is preventable if and only if a vegan diet is adopted by anyone who is in a position to', specifically excludes some (only if). If you mean it in the way: let X be the set of anyone who can go vegan, and V the set of vegans, ∀ x ∈ X, gratuitous suffering is preventable iff x ∈ V. Then that isn't true if there is a single individual whose capable of becoming vegan but whose contribution does not have an effect, which was the original concern. — shmik

To which you didn't reply.
Edit: The reason I asked you to explicitly rewrite P6 was to see if you were just tacking it on to the end since knowing if you were would clear up the ambiguity.