Karma, as it stands, has two main definitions, the first being some kind of autonomous cosmic principle which rewards or punishes people in their life according to good or bad deeds in a previous life (one already begins to wonder what the fairly neutral first life would be like), and the second being roughly the same, but without the bother of previous lives. I had an interesting discussion around this recently, which stemmed from my observation that those who profess to believe in karma, and who comment on the misfortunes of others with reference to it frequently, both with a sadistic glee when things are going badly for others, or a similarly gloating promise of misfortunes to follow; well, these said commentators aren’t so quick to admit that they deserve whichever misfortunes befall them or their loved ones, and instead will often blame the vicissitudes of fate for their problems.
So, there is an inconsistency here. My personal belief is that karma lies along the lines of wishful thinking, without any real evidence to support it, like the idea of Gaia, or heaven. The nature of past lives makes any actions therein unknowable, at least by any reliable methods that we currently possess, and so blaming someone for things they may have done to explain what may amount to bad luck seems like an overly moralistic high ground which cannot be defended.
The basic problem with the idea of karma (in regards to the past lives definition especially) is that it is unverifiable. There is no way of telling if it's true because the notion of balance is vague and hard to quantify. One man’s justice is another man’s cruel and unusual punishment. People are often very quick to judge, to dole out punishments such as bodily mutilation for rapists and beatings for those who beat. Do we imagine that some disembodied principle without an understanding of what it means to be human has a better idea of what is right for us than our own justice systems? The idea of a disembodied force being responsible for the workings of human justice doesn’t sit well with me.
Add to this the element, in many cases, of karma carrying over from supposed past lives, and the idea loses all coherence in terms of being a claim that can be tested. I don't think this bothers a lot of the people who believe in it, but that's just my way of thinking.
Even if you believe that we have only the one life, problems remain. We can all think of examples of people who have lived relatively blameless lives, and then suffered terrible catastrophes. Unless the karmic principle acts disproportionately in regards to small sins, and in that case it doesn’t seem that its influence could be considered to be in any way fair, as in generally supposed. Similarly, there are bad people who have committed horrible acts without ever paying for them in any meaningful way. Jimmy Saville springs to mind, as does history’s most infamous example, a Mr. A Hitler. These men used the escape hatch of death to escape from their retribution.
Further, karma as a motivator for morality doesn't really fit with human behaviour, in the sense that, if one finds out a friend has been in a car accident, or is seriously ill, or was robbed, one doesn't immediately think 'well, they probably deserved it'. Rather, one feels sympathy for the person who has been affected. And one sees a millionaire making even more money from a business venture, one does not think, ‘good for him, he must have been really good to deserve all that wealth.’ Well, I know I don’t, anyway.
According to karma, all those people who are poor or starving or sick or in horrible accidents, deserve no sympathy. They deserve it. Isn’t such an attitude a little sickening? A little judgemental?
There’s also the idea that those who do good are rewarded, similar to the idea of being good and earning your way into heaven. Both these ideas have as the motivation for good acts, the promise of a reward. This seems a little childish to me. Surely the motivation for an act is the right-or-wrongness of the act itself. Blessed are those who help others without expectation of karmic reward in this life or the next.
If karma is real, then logically, nothing that ever happens can be 'bad' in absolute moral terms, because it's all compensation for previous acts. (This then creates an odd cycle of bad behaviour causing bad effects, which often causes more bad behaviour, and so on.) If this is the case, then karma effectively negates the need for its own existence.
Now, I’m not saying that everyone who believes in karma thinks this way, but it is the logical conclusion of the belief system they hold. Nor am I saying that many of the people who spout these sayings have not considered the ramifications of such a system of reward and punishment. Humans are wired in such a way that we often assign meaning to things that just isn’t there, or we assume that things revolve around us in a way that they really do not. Karma is another manifestation of the way our brains work, a desire for (what we see as) justice, and a way of bringing order to a chaotic world which doesn’t care about us one way or the other. ‘Bad’ things happen, and ‘good’ things happen, and life goes on. It is all too easy to interpret an action or event in the way that we want to, and as any action or event can be fitted into the framework of karma, the whole system becomes meaningless.
I suppose I could be wrong. I guess if I am I might have some misfortune coming my way. But then again, maybe I was an excellent person in my past life. In which case, pay up, karma. Papa needs a trip to Brazil.