I have noticed a dark side of morality, both in myself and in other people. Ordinarily we think of morality as a set of rules governing 
socially acceptable behaviour. We have this internal code of conduct that we carry with us which we identify as morality. This code of conduct prescribes certain actions and prohibits others. You should help the needy; you should not lie; you should not behave in a way that degrades other human beings; you should not abuse animals; etc.
Now of course it is a generally good thing to act in accordance with a reasonable set of prescriptions. I really do appreciate those who are morally conscious as it were. People who self-consciously conduct their lives in accordance with a moral code of conduct are to be commended for their conscientiousness. There is however a tendency that we all have to be careful to avoid, especially if we are self consciously moral in our interactions with the world. This is the tendency to adopt a generally judgmental demeanour towards others. What I mean by judgment is the sense of moral outrage we get at the perceived misbehaviour of others.
The judgment arises from the failure of others to fit the narrow band of acceptable behaviour that is contained in our moral code. Often this becomes more pronounced the more the person deems themselves to be a morally good person. It also becomes more pronounced with a more detailed and refined moral system. One will often find in philosophers a highly refined and carefully considered moral code of significant complexity. I have also witnessed such a moral outlook to be accompanied by consistent and harsh judgment of behaviours and people that would otherwise have completely passed me by. It would be common to hear things like: “I detest cheerleaders because they degrade women”, or “Modern music is an abomination because it lacks any morality”, or “I look down on people who put on the aircon”, etc.
These examples I have given are actual examples I have commonly heard people say. What strikes me when listening to them is that they just do not seem to warrant moral outrage and judgment. Should we really be getting morally outraged by cheerleaders or modern music, or any number of the things we commonly get morally outraged about?
I think, even as a caution to myself, that we clearly should not. In fact I think that we should not be getting morally outraged ever. Moral is an unpleasant emotion to live with, as it is essentially a variant of anger, and as such does us no good. Moral outrage also fails to have a positive effect on the person it is pointed at. Moral outrage is expereinced as judgment and will be resisted.
Moral judgment is not a productive demeanour to adopt towards others. Essentially what moral judgment is saying is “you are bad for doing x”. A person who has made up their mind in this way can’t be helpful, they will just be experienced as self-righteous and judgmental (and will make themselves miserable in the process).
A much more useful attitude to adopt when you come across what you deem to be morally unacceptable behaviour is curiosity. It is possible to ask oneself what reasons the person has for behaving in that way with the genuine hope to come to understand them. Ultimately people do not deliberately do that which is evil. People do evil mistakenly thinking it is good, or at least whilst being insensitive to its badness as it were. People will always have what they take to be good reasons for doing things. Even brutal things like murder can be done on the basis of a conviction that the murder is justified and that the other person had it coming, or whatever. One thing you can be absolutely sure about is the human capacity to justify their misbehaviour.
I must admit however that sometimes people’s reasons for doing things just seem to be bad or fail to be sensitive to the morally relevant features of the situation. Even then we still do not need to judge them though. We must remember that understanding something does not mean that we condone it. The best response to me seems to be: “I understand why you would do this but I cannot condone it.” This type of response does not require moral outrage and judgment. You may simply point out your way of looking at it and suggest it as the right one but thereafter suspend judgment. We do not need to view others as morally bad or reprehensible. We can afford to be a bit more gentle with the moral failings of other people, whilst still refusing to condone their behaviour.
Compassion should be the foundation of our interactions with others. Without compassion our moral judgments can very quickly lead us to commit an injustice in the name of what we deem to be morally right. Indeed this seems to be precisely what is wrong with extremism. Extremist experience the world through a narrow lens of morally acceptable and unacceptable behaviour and have no compassion for those who transgress the boundaries. Though very few human beings are guilty of being extremists, we are all guilty to some degree of allowing our moral judgments to result in a fundamental negation of other people. This I think should be avoided as much as possible.