The wording of the argument would need to be altered to avoid circular reasoning. You couldn't have, "Moral behaviour cannot be based on egoism", as a premise, and, "Therefore, moral behaviour cannot be based on egoism", contained in the conclusion.

And, avoiding that problem, the conclusion wouldn't follow, since the argument doesn't preclude other possible bases for moral behaviour besides empathy. The argument considers only three possible bases, but others could be considered or proposed, and the argument would have to eliminate each and every one before validly concluding that moral behaviour can only be based on empathy.

So the answer is no, it's not.

No, it's not. Disjunctive elimination is the form:

$(P → Q), (R → Q), (P ∨ R) ⊢ Q$

Yeah, that vital "either P or R" premise is missing, for a start.

It's also not a proof by exhaustion as it isn't given in your argument that egoism, malice, and empathy are the only possible things that moral behaviour could be based on.

So, for disjunct elimination, it should be like the following:

1. If moral behaviour cannot be based on egoism, then moral behaviour is based on empathy.

2. If moral behaviour aims at reducing another persons pain, then moral behaviour is based on empathy.

3. Either moral behaviour cannot be based on egoism or moral behaviour aims at reducing another persons pain.

C. Therefore, moral behaviour is based on empathy.

But the premises are questionable. I would reject the first and third premise, and consider the second premise trivial.

The wording of the argument would need to changed to avoid circular reasoning. You couldn't have, "Moral behaviour cannot be based on egoism", as a premise, and, "Therefore, moral behaviour cannot be based on egoism", contained in the conclusion. — Sapientia

Thanks so much for your replies. I was told that this was definitely a proof by case by a chap well versed in logic, yet I'm racking my brains to see how this is so! I've attached a longer version from where this argument came from, if this helps. Can this be seen as a disjunctive elimination or proof by case? My brain is sore haha. Thanks again!

(definitions
egoism is that which aims at increasing one's own happiness.
malice is that which aims at increasing another's pain.
compassion is that which aims at reducing another's pain)

Schopenhauer states "only insofar as an action has sprung from compassion does it have moral worth; and every action resulting for any other motives has none" Schopenhauer demonstrates that actions having moral worth are motivated solely by compassion (that is, the desire for another’s well-being) in an argument by elimination (proof by case or disjunctive elimination). Schopenhauer tries to explain behavior that has moral worth- just and philanthropic actions- by uncovering the motive for these types of actions. Since he thinks of just actions as actions where people restrain their conduct to keep from hurting others, and actions of philanthropy as actions in which people seek another’s well-being, he argues that neither egoism nor malice is a motive for these actions. He thinks that in both cases the ultimate end of a persons actions is to advance others’ well-being (either by refraining from hurting them or by alleviating their pain). Because the ultimate end of egoistic actions is an agent’s own well-being, and that of malicious actions is another’s misfortune, he concludes that neither egoism nor malice is the motive for actions possessing moral worth. Hence Schopenhauer concludes these actions must necessarily be motivated by compassion since he has eliminated two of his three fundamental incentives.

In other words, he has an proof by case argument in which neither egoism or malice can be the motive for moral conduct, which leaves compassion as their source.

But, presumably, he also has an argument for his three fundamental incentives, intended to support his proof by exhaustion.

about incentives, he pretty much only states the following

"the 3 fundamental incentives are:
compassion- the desire for another's well being; malice- the desire for another's suffering
egoism- the desire for one's own well being"
then he states: “In accordance with these incentives motives will operate on man and actions will ensue".

motives, for Schopenhauer, are just objects of external perception or thoughts that can either promises happiness or suffering for an individual. e.g. I see or think of an ice cream, the perception or thought of the ice cream promises happiness for me, and then stimulates the incentive of egoism (the desire for the well-being) in my character. The combination of the motive and the incentive causes my action of going to buy an ice cream.

I think at times he does use the terms "motive" and incentive" interchangeably.

proof by exhaustion as it isn't given in your argument that egoism, malice, and empathy are the only possible things that moral behaviour could be based on. — Michael

I understand this, good point. But if we accept, just for the sake of argument, that moral conduct can only be based on egoism, malice or empathy (compassion), does the argument qualify, or can be formulated, as proof by exhaustion?

I think that Schopenhauer is wrong to rule out egoism in advance, by way of his conception of behaviour that has moral worth, and I think that him doing so conveniently paths the way for his desired conclusion. But, if you accept his terms, even if just for sake of argument, then the rest does seem to follow, and it does seem to qualify as, or could be formulated as, a proof by exhaustion.

I think that Schopenhauer is wrong to rule out egoism in advance, due to his conception of behaviour that has moral worth, and I think that him doing so conveniently paths the way for his desired conclusion. But, if you accept his terms, then the rest does seem to follow, and it does seem to qualify as, or could be formulated as, a proof by exhaustion. — Sapientia

I still don't see how it could be formulated as a proof by exhaustion? (in premise/conclusion form) In light, of our definitions of egoism, malice, and compassion, this is the best I can do, yet it still seems a bit wonky.

1. the absence of all egoistic motivation is the criterion of an action of moral worth

2. moral conduct aims at the prevention or removal of another’s suffering,

3. Thus, moral conduct cannot be due to the incentives of egoism or malice but must be stimulated by compassion, the only incentive aiming at the prevention or removal of another’s suffering.

Also, You are quite right that he does rule out egoism in advance (Kant seems to, too), and I'm not convinced he's right to do this, too. It's essentially presupposed that conduct grounded in egoism has no moral worth whatsoever; no real argument.

1. There are only three kinds of moral behaviour: egoistic, malicious, and compassionate.

2. The only kind of moral behaviour which has moral worth seeks to prevent harm to another and seeks another’s well-being, i.e. it is just and philanthropic.

3. Egoistic behaviour only has regard only for one's own well-being, and therefore cannot be philanthropic.

4. Malicious behaviour seeks to cause harm to another, and therefore cannot be just.

5. Therefore, neither egoistic behaviour nor malicious behaviour can have moral worth.

6. Compassionate behaviour seeks to prevent harm to another and seeks another’s well-being, i.e. it is just and philanthropic.

7. Therefore, the only kind of moral behaviour which has moral worth is compassionate behaviour.

1. There are only three kinds of moral behaviour: egoistic, malicious, and compassionate.

2. The only kind of moral behaviour which has moral worth seeks to prevent harm to another and seeks another’s well-being, i.e. it is just and philanthropic.

3. Egoistic behaviour only has regard only for one's own well-being, and therefore cannot be philanthropic.

4. Malicious behaviour seeks to cause harm to another, and therefore cannot be just.

5. Therefore, neither egoistic behaviour nor malicious behaviour can have moral worth.

6. Compassionate behaviour seeks to prevent harm to another and seeks another’s well-being, i.e. it is just and philanthropic.

7. Therefore, the only kind of moral behaviour which has moral worth is compassionate behaviour. — Sapientia

And I would also add...

8. Therefore (in line with the fact that egoistic behaviour, malicious behaviour, and compassionate behaviour are fundamentally grounded in the incentives of egoism, malice, and compassion, respectively) the moral incentive must be compassion.

Or rather, the only incentive for behaviour of moral worth is compassion.

sure sounds good. we now seem to have a proof by exhaustion (x2) that covers:

1. The only kind of moral behaviour which has moral worth is compassionate behaviour.
2. the only incentive for behaviour of moral worth is compassion.

Yeah, nice work. :cheer:

Too bad it doesn't mean much if you don't agree with how moral worth is being dictated.

Too bad it doesn't mean much if you don't agree with how moral worth is being dictated. — Sapientia

You make a valid point haha!