If karma isn't about cause and effect, then how can we understand its role in our lives without relying on traditional ideas of destiny and retribution?

 Cause and effect are basic principles of our universe. Attempts to dismiss them may make interesting philosophical or “spiritual” gestures, but they are not practical guides for living.

If karma isn’t about cause and effect, then what is it about?

If our actions have no causal relationship with what happens to us later, the world becomes essentially random. There would be little point in planning, acting carefully, learning from experience or trying to achieve anything, because there would be no reason to expect our actions to produce particular consequences. That is not a very practical way to live.

Karma is as much an application of cause and effect as the other laws of nature discovered by science. Those laws are completely dependent upon cause and effect. We observe that things happen in regular ways and infer a causal relationship between them.

Karma is simply the application of this principle to our actions and their consequences.

“But I don’t see the connection between the action and the reaction.”

That is certainly true in many cases. But not seeing a causal connection doesn't demonstrate that there isn't one. Karma operates across lifetimes, so the cause and effect are often separated by circumstances and time that we cannot directly observe.

Trying to understand karma without cause and effect is like drinking water and not connecting it to quenching our thirst. Is it simply an amazing coincidence that every time anyone drinks water their thirst is satisfied, with the two events having no connection whatsoever? That doesn't sound like a very intelligent proposition.

We naturally infer causation from consistent relationships. We don't demand that every cause and effect be immediately visible before accepting that the relationship exists. If a woman is pregnant we can reasonably infer that she had sex. We don’t have to have seen the act to make the inference. We see footprints and infer that someone has walked there. This is principle of inferring causation is very common in daily life.

The same principle applies when we encounter the inequalities and apparent injustices of life.

Why did this happen to me? Why was he born into such favourable circumstances while someone else was born into such terrible ones? Why was this person successful when another person wasn’t?

If there is no underlying principle connecting our actions with their consequences, then ultimately there is no meaningful answer. Events simply happen. Questioning them become pointless because there is nothing to explain beyond randomness.

Karma provides a coherent framework in which those questions can have an answer.

Circumstances do not simply appear from nowhere. They are consequences within a larger causal system, much of which extends beyond the span of a single lifetime.

A human being is distinguished precisely by the ability to ask why. While animals only experience their circumstances, humans can question them, look for causes, consider consequences and ask whether there is a deeper order behind what happens.

To deny cause and effect at the level of karma leaves us with a universe in which our actions ultimately have no intelligible relationship with our experience. I doubt any human ever lived life like that. Even if their framework is within one lifetime the basic principle of actions have consequences holds.

Karma is not an irrational addition to our understanding of cause and effect. It is an extension of the principle into the moral dimension of actions, extending over many lives.