SEE: American Humanist Association Manifesto
I do not label myself a humanists because although many humanists are atheists, some people tend to use the humanist label as if they are more acceptable than just being an "ordinary" atheist. I have work so hard all of my life for so many causes and would be considered a humanists by many people. I would say that my life philosophy is humanistic. The other problem I have with some individuals is that they are apologists for religion. No, I'm not going to condemn your little old grandmother who goes to church and I live in the real world of relatives and friends who are believers (a few anyway). So I know how to be polite and civil in social situations, but I will never use phrases such as "some of them are fine people" or "not all Muslims/Christians..." because despite the positive attributes of individual believers, they still represent a torture/death cult and give it strength with numbers.