I posted this in a blog discussion, and decided that I would like to have it in my own blog as well...
Evil is a tricky thing. It very often starts out as something the one thinks is good. For example, Power in and of itself is a good thing. If you have power, you can get things done; have more potential to accomplish good things. In 1830, somebody probably thought they were using their power to do good by setting aside land for various indigenous Native American nations so that there might be fewer conflicts with the new European Americans. Unfortunately the result of that Indian Removal Act is now called 'The Trail of Tears', and is (quite justly) viewed as a great evil (not to mention the countless humanitarian travesties that have resulted since then).
I think that we know things like that are evil by comparison against good. It would have been good if no-one had died on the Trail; if people could live alongside each other without feeling threatened by cultural differences. Evil only exists as opposition to (or a twisting of) something good. Even the evilest people in history (e.g. Nero, Hitler, Mussolini) in some way thought that they were right, though the fruits of their actions (the deaths of innocents) show the evil within born of self-supremacy and excessive narcissistic selfishness. Their actions were also the result of thinking that they knew best, but without listening to or having empathy for the people they persecuted, oppressed, and murdered, they manifested some of the worst evils humans can execute.
Kindness requires no knowledge of evil. One does not do something kind by twisting a bad/evil thought to kindness, but one of the worst things an individual can do is to make you think they are being kind whilst betraying you in your trust. To forgive someone who has beguiled you is a difficult thing, let alone trust. However, forgiveness is a kindness in itself (first and foremost it is a kindness to your own spirit to let go of the pain and anger). Kindness only requires empathic love which puts one into the shoes of another (what people used to call charity). Good is good all by itself.