Karma is one of those words that have launched into our English language with a vengeance. Mostly people take it in a new age sense, as cosmic payback. I suspect the majority of us use the word, when we use it, in that sense, where there is some cosmic zero sum and where if you do good, good will come to you, and if you do bad, well, what's coming is your fault. It's summed up nicely in the phrase "what goes around, comes around."
No doubt in East Asia there are many who understand karma pretty much this way. The word is from the Indian subcontinent with roots that go way back. People who like etymology suggest it derives from the hypothetical proto-Indo-European "kri" which seems to mean "well made." Karma means different things to Hindus, Buddhists and Jains, and actually within these religions there are minor and major variations.
In most of these traditions there's an intimate connection between karma and rebirth. For instance in classic Buddhist thought karma is all about one's intentions, not actions, and it is those intentions as they arise that create new lives.
I'm just not into post-mortem reanimation. I see no compelling evidence for it, despite the occasional report based on someone's near death experience (near death, as the skeptics point out, not death...) for a life after life, I've never seen an account that makes me suspect its more than wishful thinking. For whatever reason I don't feel a need for another life, this one is quite full enough, thank you. And unless some compelling evidence presents (please, I don't need more near death stories, thank you) that doesn't have easier explanations, I'm going to work on the assumption of one life.
(Personally I find the idea of life and then nothing after death not quite the point. It assumes a universe with a point a and a point b, and that we live somewhere on that line with a time before us and a time after us. It's not that it's not true, but that it isn't enough of the truth. It seems to me the universe is rather larger and messier, and while our individual consciousness may be a little light among many other things within something very big, that little light is in fact part of that much bigger thing, which if we open our hearts and are just a little bit lucky, we get to notice. And with this noticing there is a certain grace and even joy. With it being mortal is no problem.)
For many karma is a way of addressing that nasty fact on the ground where bad things happen to good people and bad people often flourish, and never seem to get their just deserts. Goes around, comes around. Adding in something after this life can help, with a suitable punishment or reward one way or another. For those who are uncomfortable with the sequence of lives or just one life and reward or punishment, this karma get you rewarded and or punished here. However the evidence of our eyes makes this pared down version of karma equally hard to swallow. As the man said, the rain falls on the just and the unjust alike...
This one life is enough for me. And it is one heck of a mystery. And a mystery worth exploring without adding in any extra bits. All this getting around to my point, I think there are aspects to karma that are helpful in that exploring without having to add extra bits.
As far back as the Hindu spiritual classic, the Upanishads, karma has an ethical connotation, as the Brihadaranyaka Upanishad tells us, "It is true, a person becomes good through good actions, or evil through evil actions." Now, that understanding, I think worth noting, isn't precisely the cosmic scale sort of thing in new age karma. Rather it is a bit more like that bit of wisdom I've found attributed to "Chinese wisdom," Ralph Waldo Emerson, and most recently to the Seven Habits author Stephen Covey.
"Sow a thought, reap an action; sow an action, reap a habit; sow a habit, reap a character; sow a character, reap a destiny."
This view of karma makes a lot of sense to me. It isn't about payback, or evening scores. Rather it sings out of the mystery of interconnectedness, about choices, and consequences in a way that seems true.
Each thought, each action, is something like a brick in the edifice that we think of as ourselves. And out of each thought and actions something is built. And a lot of it by our own hand. But, it doesn't lead to fortune or poverty. It is more fundamental.
Action. Habit. Character. Destiny.
So, if I do something, whatever that something is, it is unlikely it will lead to a simple reaction or response. The universe is too big, and too many things are going on at the same time. Very few things, particularly in our human lives, can be traced to a single action. So, that thought, that action, to shift the metaphor, is a thread we add to the weaving of our lives.
By itself, not so much.
But then add another thread, and then another, each woven into the great fabric, it begins to matter a lot.
Perhaps even for everything.
Rather more important, I think, than dreams of just deserts...