"If you care about suffering, you will do something about it."
Of course, this is also rather vague in prescription - to what extent should you go to do something about suffering?
I have mulled about this general idea for a long while now, I basically have come to realize that I see no way of justifying self-indulgent actions while others are worse off.
For me (and I think for most everyone else who isn't lacking in compassion and empathy - i.e. sociopaths, psychopaths, selfish individuals, most politicians, etc.), it seems wrong to ignore someone who just broke their leg down the block and is screaming in pain as their femur extends out of their leg at a gross angle. Almost everyone, I think, would feel obligated to aid this person, and also expect others to do the same in such a situation. You could at least call 9-11.
But this also leads to a very slippery slope - at what point do you no longer have a reasonable obligation to help someone? What if this person lived two blocks down, would you still need to help them? What if they lived in a different city, and you saw them through binoculars? What if you theoretically could help them if you drove your car over to the city - is your annoyance with driving a few miles really comparable to the pain this individual is in?
We cannot help those whom we do not know need help. But, in fact, we know a great deal of people, even if it is impersonal, that require aid. And we also know of general facts of society and life in general - the poor get fucked by the rich, the prey gets its neck torn out by the predator, we never seem to be satisfied and in fact often feel pain, etc. And so if we do not know of anyone who needs help, certainly it is possible for us to go out and find those who need help, for we know that someone, somewhere, is in need. We need not sit here and wait for those in need to find us.
This is, of course, largely a consequentialist argument. But I think it is a very strong argument, for at the very least we can appeal to egoism and show how, if we were in extreme pain ourselves, we would like it if someone helped us. I'm sure anyone's reluctance to help someone in need pales in comparison to the pain this person is experiencing.
So in general I think there really is no other position to take other than to accept that those who are worse-off than we are should be sought out and helped to the best of our abilities - in other words, if the cost of us helping them is reasonably lower than the relief the victim experiences, we have a moral obligation to do so.
I've made my own pessimistic views known. But definitely one thing I disagree strongly with when it comes to living as a "pessimist" is the general tendency to advocate isolation, asceticism, and/or the intellectually self-centered, self-indulgent life advocated by these cherished melancholic thinkers. It just doesn't make any sense - if you really believe that there is this much suffering and decay in the world, the worst thing you could do is to propagate this suffering and decay. Having a negative outlook and yet continuing to live an affirmative life is logically contradictory. And, I think, a legitimate understanding of suffering (by compassion and empathy) leads to the dissolution of the doing/allowing distinction, which leads to the conclusion that standing idly by is equivalent, or at least no-more praiseworthy, than intentionally causing harm.
This leads to uncomfortable/guilty conclusions that I think modern ethicists have made an entire speculative field out of to try to mitigate: essentially much of modern ethics ends up being apologetics for not doing enough, or being a lazy, selfish individual, i.e. justifying inherent human dispositions as if they are on par with our apparent moral obligations.
Some of these conclusions would be as follows: the complete abandonment of non-effective-utility intellectual enterprises, including but not limited to much of theoretical physics, evolutionary biology, astronomy, psychology, as well as much or all of the arts and humanities, and especially professional sports and entertainment. For when placed on utility scales, they are largely worthless and exorbitantly wasteful in that they self-indulge while ignoring the plight of others. It also means a radical change in lifestyle, including but not limited to: veganism (or at least vegetarianism), ethically-mandatory political action, and most of all the complete abandonment of one's own personal desires in order to help others.
If you think this is too much to ask for, you need only imagine yourself in the situation of a person in need. And to tell yourself that you are "lucky" for being better off is incredibly selfish.
But I'm under no delusions that this is actually feasible. We are human beings after all, and won't be motivated to abandon all our dreams and desires for moral duty. But I think it's something rather important, and saddening, to point out how incredibly narcissistic we all are, how incredibly immoral we are, at the expense of everyone else. Because once we identify a problem, we can at least try to be better.