I wish I knew the source of the following: indifference to your fellow human being is the worst kind of inhumanity. This isn’t about “live and let live”, this is “live and who cares”.
Of course, torture, murder and the like are all very bad, too. But, the idea is that with something like torture, a person matters enough that someone else feels the need to do them harm. Even in Hell, someone has meaning.
To see someone suffering and to ignore them implies that they lack any kind of significance. To deem another person as worthless is to consider them not human — not deserving of anything.
There are many ways to make the world a better place; one sure way is to increase empathy.
Update (2010-11-13): The starting point of this blog entry is a George Bernard Shaw quote: “Indifference is the essence of inhumanity.”