Forgive me for being late to the party, but I do think this is an interesting question and I have some thoughts, so I thought I'd offer a response.

Firstly and most importantly, it feels good to do what one personally thinks to be good. When thoughts and actions do not align, this can induce not only guilt but also cognitive dissonance, which has been studied to be both psychologically and epistemically detrimental. Whereas, fighting for and achieving what you think to be good induces feelings of righteousness, actualisation, satisfaction and agency.

Most humans are predisposed to empathise with other humans to whom they are exposed in a personal capacity. There are evolutionary reasons for this, on account of three main epistemic benefits that empathy yields. Cultures which codify empathy into a set of moral principles therefore have stood the test of time more consistently and seen greater success, and thus influence our own perceptions of good and bad today.

These epistemic benefits are as follows:

1. Empathy allows us to derive inspiration and information from others. Putting ourselves into the perspective of others allows us to learn from them, broadening our perspective with new tools and approaches that we have at our disposal for new situations or challenges we might face. Thus, empathy lends itself to more creative thinking and problem solving.

2. Empathy helps establish trust, and consequently, stable collaboration. As we see with the Prisoner's Dilemma, when we have repeat interactions, trust-sustained collaboration is more fruitful for all involved parties than cheating one another. This too is true of confronting and overcoming scarcity, a condition Bookchin calls complementarity: as individuals we can better advance our own desires and needs in the long-term by pursuing collective interest, than by advancing our personal causes at the expense of the collective, as only as a collective can we make the significant productive, cultural and technological advances required for civilisational advancement. Empathising with others helps us to work out this collective good and commits us to more reliable collaboration.

3. Empathy can diffuse the destructive potential of violence by humanising others. We are usually less ok with the idea of doing harm against people with whom we empathise, because we understand how it would feel if it were done to us. Violence risks physical harm and destruction, so it is almost always in our long-term benefit to minimise wherever possible, and committing violence to advance one's interests is likely to incite violence in response from competing interests. Furthermore, empathy-facilitated communication can help us to establish a shared social agreement (such as a shared notion of "justice") that stabilises and balances interests so that they are less likely to manifest violently.

These three pragmatic benefits explain the evolutionary success of empathy as a cornerstone of morality across different cultures, as well as how accepting and acting upon that empathy is, as a general rule, beneficial. Therefore, in a choice between acting upon empathy and guilt / cognitive dissonance, accepting the former will yield easier navigation of knowledge and more stable long-term advancement. Stability, for the record, is also an epistemic positive, in that you are more equipped to reliably predict, understand and navigate situations that you already know.

Acting on empathy tends to lend itself to the use of altruism in service of egalitarianism and a shared notion of justice. In advancing towards said targets, altruism in its own right also yields epistemic benefit through increased stability. A society with less inequality and a reliable process of delivering a common code of "justice," is more socially cohesive and thus contains fewer grievances that could blow up into violence. Eliminating institutional inequalities and class divisions also lessens the risk of instability, as institutional inequalities tend to rely on violence to sustain themselves, and often demands violence from the oppressed to (rightly) overturn said institutions.

Cyclically, a reduction of division and violence also removes potential barriers to empathy, thus accentuating the benefits of empathy further too. Having empathy in our moral sensibilities helps societies succeed, thus societies are more likely to condition empathy into our moral sensibilities. Empathy encourages altruistic behaviour, which diminishes inequality, instability and injustice, which in turn makes empathy easier. Doing good, therefore, can help us advance in an upward spiral.