What is Humanism to you?

Maybe this belongs in another category besides the Water Cooler, but I'd just like to know what everyone thinks of Humanism. I consider myself a humanist and I know what it means to me. How do you view it (whether you consider yourself one or not)? I'm interested in what people think humanism entails and what it excludes. Some things are obvious, but others might disagree on some. Is it inherently atheistic/antitheistic or just compatible with it? I'm also interested in how one refutes claims like "Humanism is narcissism." or that it is inherently selfish. I have my own answers to these questions but I'd really like to hear what the community has to say on it.