No wrong no right,
I'm gonna tell you there's no black and no white.
Queen, "One Vision"

A small addition to the previous post.

Dividing people (and other things) into black and white on the basis of some particular feature of them is one of the biggest mistakes one can make. Unfortunately, our mind is lazy. It is much easier for us to sort a hundred elements out into two (three, four, ten) groups by some common criteria and operate with those N groups, than to put each one to a separate personal group and deal with 100 groups instead. Sometimes this is called abstracting. Naturally, abstracting is good when used in maths or biology, but it distorts our vision when applied to real-world or social stuff.

Sometimes this feature of our mind is exploited by unfair people. The teams of candidates of presidential/governmental races often try to blacken the opposite candidate by showing them as adulterer, a person of doubtful character and so on. Well, it is difficult for me to understand the relation between PM's sexual temperament and their economical and manager's skills (needed for the state to prosper).

I try to classify the things as vectors of different essential properties. For instance, a typical vector of a person is (name, sex, age, sense of humour (1-10), kindness (1-10), intellectual level (-1-10), positiveness (1-10), honesty, appearance, physical skills, risk-ability, ..., smoking (yes/no), ...). This relates to all people, not only to friends (politics have some of the properties grayed, e.g. honesty ;)). The properties are mostly orthogonal, and thus such classification helps not to sort people into black and white, stupid and clever, or honest and dishonest. Really, there are quite a few properties to consider, and the presence of negative ones does not mean the absence of positive ones.