What's the role of altruism in Buddhism? In discussions about how to translate words such as averena (a negation of some quality), I've seen two general kinds of answer: or the compound word is not just the negation of the suffix, but its polar opposite; or the compound word is just a negation of the suffix. In the case of averena, the first method renders 'love', 'loving-kindness', or whatever translation is used for metta; in the second, 'non-hatred' is the translated concept.
This discussion (on how to translate negations) has made me think on the role of altruism in Buddhism (which can be seen as unrelated to the root topic at first).
I know there are suttas like AN 11.1 which explain the importance of virtous conduct to the development of the other factors of the path. These suttas seem to indicate that the main purpose of ethics is to liberate one's own mind (which, of course, makes one a positive influence on others). But also there are suttas like SN 47.19 state that looking for others is key as well. I don't see both positions as contradictory, but as complementary. And we have as well the teachings on the practice of Brahmaviharas, with metta, karuna, mudita and upekkha as mind-states to cultivate.
Despite all of the above, in the descriptions of the Noble Eightfold Path (which I understand as containing all that's sufficient and necessary for &quot;moving&quot; from sotapanna to arahant) Samma Sankappa is broken down as nekkhamma, abyapada and avihimsa, with at least two of those three factors being words with negative prefixes, which depending on how you translate negations, could indicate the predominant role of the absence of the unwholesome over the presence of the polar opposite of the unwholesome, i.e. non-hatred over loving-kindness.
After considering all of above, here's the question:
What would you say is the role of altruism (understood as an active effort for improving the quality of life of other, whether by teaching the Dhamma, giving advice, getting involved in education, improving access to material conditions, etc.) and other forms of positive (as &quot;presence of something&quot;, not as &quot;good&quot;) wholesome deeds in the different buddhist traditions?
How important is to buddhist to make the world a better place, not just by developing negative (as &quot;absence of something&quot;, not as &quot;bad&quot;) wholesome qualities, but by changing the general conditions of the world?
EDIT: I'd like to add a new question to give more perspective:
As santa100 has noted, the negation of the unwholesome includes the positive wholesome deeds. However, it'd be interesting to know how important is for the buddhist practice to actively engage in positive wholesome conduct, and why does it matter. With that I mean: what effects does have on the world and on ones own mind to do those positive deeds?
My motivation for gaining some perspective on this is to know what to think about the idea of buddhism being not altruistic enough.
I'd appreciate personal points of view and/or references to buddhist teaching/discourses that support your views.
I apologize for any wrong understanding of the Dhamma I could have expressed in the premisses. Please, correct me if that's the case.
Altruism is defined as the belief in or practice of disinterested and selfless concern for the well-being of others.
With respect to Buddhism, altruism is therefore:

AN4.95:1.4: one who practices to benefit others, but not themselves;

Quite significantly, Buddhism goes further:

AN4.95:3.2: The person who practices to benefit themselves, but not others, is better than both of those.

Importantly, those who practice to benefit themselves but not others are not practicing stinginess in the conventional sense. Rather, those who practice to benefit themselves but not others are in seclusion extinguishing defilements of self-involvement.
Ultimately, Buddhists ideally practice to benefit themselves and others:

AN4.95:3.3: But the person who practices to benefit both themselves and others is the foremost, best, chief, highest, and finest of the four.

When I first read this, I found it a startling departure from my preconception that altruism was the highest ideal.
A parallel consideration here is that altruism concerns itself with &quot;good deeds&quot;. Here, too, the Buddha says quite simply:

AN4.233:1.3: There are dark deeds with dark results; bright deeds with bright results;

But the Buddha goes on to say more:

AN4.233:1.5: dark and bright deeds with dark and bright results; and neither dark nor bright deeds with neither dark nor bright results, which lead to the ending of deeds.

We're all familiar with the muddle of dark and bright. But what is the fourth goal?

AN4.233:5.1: And what are neither dark nor bright deeds with neither dark nor bright results, which lead to the ending of deeds?  It’s the intention to give up dark deeds with dark results, bright deeds with bright results, and both dark and bright deeds with both dark and bright results.

That fourth goal leads to the end of suffering for all.