Great comments on new #namethetrait video

[brimstoneSalad]

The point is you could potentially define a new set using the axiom of schema replacement, but you wouldn't be talking about the humans provided you defined humans as having a certain set of traits.

Seems like "human" is just defined with the trait "humanity", which is all P1 refers to.

Are you talking about the power set of the set of traits humans have ? If so it would mean "we" would reference many things and would be difficult to have it widely accepted.

That's one of the problems mentioned; it kind of breaks down when you're asked to still call a cow "you" despite everything that defines you being removed.
It seems like Ask Yourself believes in a somewhat magical property of consciousness.

Maybe "we" just refers to an irreducible non-naturalistic existential property of "us-ness" that has no clear meaning.

It's a problem in his argument.

I don't think it's a problem for the correction, since P5 grounds it in objective behavioral indications of value.
"P5 - Any attempted defense of personal interests is an indication of self-value"
We don't even need to talk about "we"; whatever results from the property addition/removal, if it defends its interests it has self-value.

I still think a viable option here is to define human as having a certain set of traits X and let the user of the argument define his own set. Then proceed by "creating" an instance which doesn't have a particular trait or set of traits. No mention of "we" or "humans", those become irrelevant.

That might work.

( the specific user of the argument would decide if he sees the instance as a human or not making sure it doesn't introduce definitions inconsistencies along the way ).

So the first "human" set is non-exclusive? Other sets could be human too? That makes sense for the sake of argument, so we don't require an exhaustive definition of human.
Where would definition inconsistencies come from? The definition of human might be diluted, but aside from that all we're looking for are perfect negations, right?

Do we assume P1 just indicates that all humans happen to have morally valuable traits, or can we assume that humanity is that trait?

So we'd be comparing animals to a new instance (which may or may not be human, and may or may not have moral value if it is not human), such that the new instance lacks the same proposed trait the animals lack, and if the new instance also lacks moral value then so do the animals (that is, if a trait were required to determine moral value, which it is not according to the original formulation...).

I would be curious to know what AY would answer to this.

I agree... but I don't think he would take the time to try to understand the question.

What does he define "we" to be exactly ? I do not know if he would be then pushed to remove this reference from the argument completely.

Ask Yourself being pushed to correct his argument? Clearly you have not met the guy.

I think he has possibly come to understand that his argument is not valid, but he's not going to go back on it. Too much investment.

Can you sign up to the wiki and help with the article?

http://philosophicalvegan.com/wiki/index.php/NameTheTrait

I'd love to include the formulations you and DrSinger have been discussing here.

same to DrSinger

...

Mind signing up on the Wiki?

[DrSinger]

Signed up Would be happy to contribute to the wiki wherever I can. I think there's a lot to be said for the role of moral realism and the notion of 'moral facts' in vegan argumentation. Often times arguments get to the point of 'my morals vs your morals', or get stuck with meat eaters talking descriptively about ethics when the conversation is about normative ethics (i think more vegans should be aware of this distinction). Would love to see an article relating to moral facts, realism etc., since I think more vegans should be aware it. I would be happy to learn about it and contribute.

I would post this formulation on the wiki if we can get to an agreement about whether it's valid or accurate. At the moment I think the part in P2 'x∈H' needs work.

P1: ∀x∈H: M(x)
P2: ∄t∈T(x∈H (-T(x,t) -> -M(x)))
C: ∀y∈A: M(y)

H is the set of all humans
A is the set of all animals
T is the set of all traits absent in animals

P1: All humans have moral value
P2: there exists no trait absent in animals, that if absent in a human would cause them to have no moral value.
C: All animals have moral value

[brimstoneSalad]

I would post this formulation on the wiki if we can get to an agreement about whether it's valid or accurate. At the moment I think the part in P2 'x∈H' needs work.

I assume you mean a valid translation, rather than the logic being valid.
Thanks!

I'll try to dig into it this weekend (tomorrow is pretty busy, and I need to finish a few things tonight). I look forward to seeing Nightcell001's response.

Think we can work out a formal proof for why it doesn't follow once we agree on the form?

[brimstoneSalad]

I dropped it in for the time being; I'll update it as we come up with corrections here.
I haven't publicly shared that wiki link yet, so probably only we and a couple others I've asked for feedback from can see that.

Pleased to report the symbols seem to come out OK (on my browser anyway).

We may want to refactor P2 taking this into consideration:
http://philosophicalvegan.com/wiki/index.php/NameTheTrait#Meaning_of_.22moral_value.22
"We" or "I" seems to be important.
I'm not sure how to do that yet.

[DrSinger]

The symbols come out nicely for me as well. I wouldn't be able to prove it doesn't follow without reading up/learning how to. Interested to see what nightcell has to say regarding the attempt, he has a far better knowledge of logic than me.

My thoughts regarding the humans vs ourselves problem in P2 is that humans and ourselves refer to the same thing, i.e. you could replace ourselves for humans at the end of the sentence. If they are referring to two different entities I can't see that the sentence makes any sense. But perhaps I'm just not seeing the nuance here.

[PhilRisk]

I would post this formulation on the wiki if we can get to an agreement about whether it's valid or accurate. At the moment I think the part in P2 'x∈H' needs work.

P1: ∀x∈H: M(x)
P2: ∄t∈T(x∈H (-T(x,t) -> -M(x)))
C: ∀y∈A: M(y)

H is the set of all humans
A is the set of all animals
T is the set of all traits absent in animals

P1: All humans have moral value
P2: there exists no trait absent in animals, that if absent in a human would cause them to have no moral value.
C: All animals have moral value

One problem is indeed 'x∈H', because the quantifier is missing. Otherwise the variable is free and it is no complete statement. I think a simple change to '∀x∈H' would do.
The other problem is '-T(x,t)', because that is non-defined relation. I realized you kept this in the argument from former versions as a relation. It can be changed to another letter, because T is now denotin the set of traits. A candidate for P2 plus additional definition of F(x,y). But I am not sure if this completely fits the syntax of Nightcell001.

P2: ∄t∈T: (∀x∈H: (-F(x,t) -> -M(x)))

F(x,y) is the relation, x has trait y

Think we can work out a formal proof for why it doesn't follow once we agree on the form?

That might not be that easy, because predicate logic is semidecidable.
https://en.wikipedia.org/wiki/Decidability_%28logic%29#Semidecidability

One additional comment on P2 following from P1. Formally, I was only able to show it follows from P1 that P2 or all humans have all traits in T.

[DrSinger]

Nightcell seemed to think there was an issue quantifying over all x, which I don't fully understand, perhaps you would have a better take on it. I'll update the symbolic representation to as you have it there on the wiki.

I guess I could say for all x an element of the set all humans, for all y an element of the set all animals, as you suggested. Would it be fine then?

Yep, it's fine now. Thought you could remove the predicates H() and A() since they will evaluate to true all the time. Your statement becomes :

∄t∈T(∀x∈H ∀y∈A ((-T(y,t)^ -T(x,t)) -> -M(x)))

And now comes the second problem. This doesn't really translate P2 of AY which says there is no trait absent in animals which if absent in humans .... Meaning it is present in human. Your statement says that :
- It is false to say that there exist a trait ...
So If we managed to find a trait that evaluate the rest of the statement to True, the statement will become false by the negation.

If we take the trait to be "have two hands" : "((-T(y,t)^ -T(x,t))" evaluate to False ( because humans have two hands ), which make the implication vacuously True once again.

That falls back to my previous remarks :

( an equivalent advice apply to the existential quantifier, which should be used with conjunction rather than implication )

I hope I'm not making your brain to heat up unnecessarily, I know the feeling !

[PhilRisk]

Nightcell seemed to think there was an issue quantifying over all x, which I don't fully understand, perhaps you would have a better take on it. I'll update the symbolic representation to as you have it there on the wiki.

I did not really consider whether or not it is a good formalization of the informal P2.
The problem of Nightcell is, that the implication is true if the antecedent is false. Therefore, the trait "having two hand" fulfills the condition and a trait exists. Therefore P2 is false.

The advice by Nightcell is to use the conjunction in case of the existential quantifier.
Then the formalization might be:

P2: ∄t∈T: (∀x∈H: (-F(x,t) & -M(x)))

As a first remark. Now P2 does in fact follow from P1, because for all humans have moral value, but I am not sure how to interpret '∄t∈T: (∀x∈H:' in the used syntax.

But is this a good formalization of P2?
P2 is false if there is such a trait no animal has in T and all humans don't have this trait either and no human is of moral value. This is totally inadequate.

So an alternative is this. I will not use the sets, because I prefer to constrain quantifiers by predicates:

∄t(∀y(Ay -> -Fyt)&∀x((Hx&-Fxt) -> -Mx))

Whether this is really adequate I am not certainly sure.

[Nightcell001]

Hey guys ! I should definitely check this page more often !

I'll try to dig into it this weekend (tomorrow is pretty busy, and I need to finish a few things tonight). I look forward to seeing Nightcell001's response.

I am pretty busy as well, there is much I want to say but try to make my comments short because of the time consumption. I have a full time job that is pretty tough on me. I will definitely spend some hours on a First order logic formulation on NTT that will try to alleviate the "we", "humans" problem in it.

Can you sign up to the wiki and help with the article?

For sure, I'll be glad to. Noble effort here.

I haven't publicly shared that wiki link yet, so probably only we and a couple others I've asked for feedback from can see that.

That's probably a good thing. Although the wiki is pretty dense as I can see.

Ask Yourself being pushed to correct his argument? Clearly you have not met the guy.

I saw your intervention with AY on ThinkClub channel. I find it extremely interesting when he said something like :

There is a reason why my argument is so popular and yours is not ...

I have trouble interacting with all my family members and most of my friends because of my reasoning. I sure hope it's not because my arguments are weak or uninteresting. But people usually lose patience with me. The so called "appeal to popularity" seem to be strong with AY.

Pleased to report the symbols seem to come out OK (on my browser anyway).

What symbols are you talking about ? If it is the logical symbols then for me it is not displayed correctly in my browser. I could probably create a png image using latex to have something clean on my hand, modifications by other member will require re-generating the png though ....

Interested to see what nightcell has to say regarding the attempt

Will take a look shortly, I have no meetings today, I will try to squeeze in some time.

That might not be that easy, because predicate logic is semidecidable.

Yes. It is difficult to prove formally that the argument doesn't follow. The best shot at refuting the formal validity would be to derive a contradiction which in the case of NTT would be deriving a non contradiction. This is really extra work because if AY claim that his argument leads to a contradiction he has the task to show how, and not by informally saying " accepting and rejecting killing based on X simultaneously is a contradiction ". I still have no clue on the system of deduction he is using. If someone knows maybe if you can share it here ? I understand the fact that the people not interested in Logic would have trouble understanding formal arguments and the task of veganism is to convey the message despite of that. But then once again he should accept his argument to be informal.

Nightcell seemed to think there was an issue quantifying over all x, which I don't fully understand

I'm sorry about that. Quantification over X is no problem for sure. We should just be careful how we are using it. It is easy to say things we don't want to say with this. Using quantifier free formulas with free variable is indeed incorrect. Also :

∀x∈H

is the contracted version of :

∀x: x∈H ->

So "∀x∈H" has to be really thought of an implication. Meaning the proposition resulting will be True if x is not in H.

But is this a good formalization of P2?
P2 is false if there is such a trait no animal has in T and all humans don't have this trait either and no human is of moral value. This is totally inadequate.

So an alternative is this. I will not use the sets, because I prefer to constrain quantifiers by predicates:

∄t(∀y(Ay -> -Fyt)&∀x((Hx&-Fxt) -> -Mx))

Whether this is really adequate I am not certainly sure.

I also prefer to constrain quantifiers by predicates as it is more easily testable again a specific structure.I will take a look at your answer when I have a little time. And definitely would love to have feedback on an attempt of translating NTT I will be producing in the next few days.

[Nightcell001]

∄t(∀y(Ay -> -Fyt)&∀x((Hx&-Fxt) -> -Mx))

Whether this is really adequate I am not certainly sure.

We can decompose the statement in two equivalent statements by conjunction elimination :

∄t(∀y(Ay -> -Fyt)&∀x((Hx&-Fxt) -> -Mx))

would become :

∄t(∀y(Ay -> -Fyt))
∄t:∀x((Hx&-Fxt) -> -Mx))

According to P1 "∄t:∀x((Hx&-Fxt) -> -Mx)" will evaluate to True. And "∄t(∀y(Ay -> -Fyt)" would be evaluated to false by finding the trait to be "human DNA". Every animals lack this trait.