Reasons and Excuses
I don't believe in either contra-causal free will or objective morality. I don't know many skeptics who believe in either of those, but I do run into a lot of skeptics who seem to feel that bad behavior can be excused by explaining that the behavior was the result of forces outside of the control of the actor, such as mental illness or a history of oppression. I find these things to be in conflict.
First, without objective morality, calling an act or a person "better" or "worse" than a different act or person becomes merely a subjective judgment, based on the speaker's preference. When I say, for instance, that being honest with your friends is better than lying to your friends, what I really mean is that I prefer to live in a world where people are honest with their friends, not that there is anything objectively superior about such behavior. When I say that "Sam is a better person than Pat," what I mean is that Sam helps move the state of the world and/or my subjective experience of the world toward my preferred ideal more or better than Pat does.
Second, without contra-causal free will, all actions are caused by external forces, and nobody is truly responsible for hir own actions. The main implication of this view is that all evaluations* of someone's behavior must be forward-looking. Traditionally, the morality of an action is judged in a backward-looking way. An act's morality, and its associated blame or praise, has traditionally been based on an evaluation of what exactly the actor did what what hir motivation was at the time of the behavior. The focus is on the past. When you take contra-causal free will out of the equation, this approach makes no sense. Because all actions are caused by external factors, the only relevant inquiry into the myriad causes of a person's behavior is the extent to which an understanding of such causes allows one to predict and/or influence that person's future behavior.
Consider two parents who beats their children. Alex was abused as a child, and beat hir children because that is hir only understanding of the parent-child relationship.** Assuming that the statistic that 70% of abused children turn into abusive adults is true. Terry has lived a life of luxury and privilege, and beats hir children because ze has anger management issues. Which one is morally worse?
The intuitive answer is that Terry is worse, because Alex is a victim of circumstance, and Terry seems more in control of hir own behavior. However, without a belief in contra-causal free will, one must view everyone as a victim of circumstance. Terry has no more meaningful "choice" in hir behavior than Alex does.
The reasonable inquiry in such a circumstance is: what is each person likely to do in the future? How will each respond to efforts at rehabilitation? What sort of conditioning*** must each be given in order to prevent future instances of child abuse? It may very well turn out to be the case that Alex's behavior is more ingrained, and thus Alex must be subject to stronger conditioning & stricter monitoring in order to prevent future abuse. While this is intuitively unjust, it is the only rational conclusion.
This is not entirely counter-intuitive. One of the reason that crimes of passion are punished less than crimes involving forethought is that crimes of passion are less likely to be repeated. It is also the reason that repeat offenders are punished more harshly than one-time offenders.
The idea that all evaluations of a person's behavior must be forward-looking is equally applicable to all acts and personality traits. This comes into conflict with our natural sympathy for the oppressed. Skeptical communities tend to be liberal communities, which are sensitive to things like oppression, privilege, poverty, society's influence, brain chemistry, and similar concepts. This is generally a strength of the community. Often, however, some members of the community (and a number of people that I know personally) make use of such concepts in order to excuse bad behavior.
Consider mental illness. Many people have diagnosed mental illnesses that cause them to behave in ways that I (and many others) see as unacceptable from healthy people. I do not think this is a controversial statement. Often, the behavior caused by such illness is exactly why it is classified as an illness in the first place. Mental illnesses can cause people to be excessively prone to anger and violence, to have poor social skills, to behave irrationally, to suffer delusions, and many other behaviors that I consider "bad." This is not a moral judgment, as I do not believe in morality. I have tremendous sympathy for those who suffer from such things, often because they recognize the illness in themselves, and they find it much more objectionable than I do.
The same goes for victims of oppression. Oppression (especially of women and minority groups) is rampant in our society, and oppression can make it completely understandable why someone would be more suspicious, hostile, or quick to anger than someone more privileged. An understanding of oppression and privilege is critical for anyone who actually cares about other people and/or society. The skeptical community's awareness of such is growing, and the community is much better for it.
However, mental illness and oppression are not excuses for bad behavior. They are merely reasons. The fact that such are out of the actor's control does not differentiate them from any other explanation for a bad act. The biggest jerk in the world is a jerk for reasons outside of hir control. Any evaluation of the person's behavior, to be at all useful, must be forward-looking. Some mental illnesses make a person completely intolerable, and I don't think there's any shame in saying so. Sometimes a person's history of oppression can give hir a giant chip on hir shoulder such that ze is unpleasant to be around. It doesn't mean that we shouldn't be sympathetic, but neither does it mean that we should view such behavior as any more (or less) forgivable or tolerable than someone who does the same thing for a different reason.
This is not to say that reasons for bad behavior are irrelevant. On the contrary, understanding of a person's reasons for their behavior is critical to an understanding of how likely ze is to repeat such behavior. Often, a diagnosed mental illness is much easier to deal with than a standard personality flaw, because treatment is available. An understand of an oppressed person's history makes it easier to predict what will trigger the objectionable behavior. These are all very relevant lines of reasoning.
However, understanding a person's reasons for behaving the way that they do is only part of the inquiry. I think that the relevant inquiry when evaluating someone's actions is an inquiry into that person's future behavior. This is the inquiry which allows me to decide if I consider that person a force for good or bad (in the subjective sense, as I've defined them above).
Everyone has reasons for their behavior which are outside of hir control. A reason is not an excuse, and we shouldn't treat it as such.
Side note - this post has concentrated on explaining away a person's bad behavior for what I consider bad reasons. I see these concepts as equally applicable to the excessive glorifying of a person's good behavior. Just as all bad acts are the result of forces outside of a person's control, so are all good acts.
* When I talk about evaluations of a person's behavior, I mean the process by which we, as individuals, decide things like what role we want a person to have in or lives, how close we can/should be to someone, how often we want such person around, how attracted we are, how dangerous someone is to us, etc. Such decisions are reliant upon the ability to make accurate predictions of a person's future behavior, which is why that's where my focus is. Society also makes collective evaluations, through the legal system, to which I think these principles are equally valid. However, for purposes of this discussion, I'm concentrating on individual evaluations.
** Disclaimer: I know nothing about the psychology of child abuse. This may be a completely unrealistic hypothetical. Please consider it only for purposes of the point being illustrated.
*** I use "conditioning" in place of "punishment," because I don't think punishment is very effective at rehabiliting antisocial inclinations, notwithstanding that it is the only system that our society uses. ______________________________________