Next to the concept of non-self, perhaps the most misunderstood concept in Buddhism is the concept of kamma (karma in Sanskrit) and rebirth. Rebirth occurs with every moment. Actually, there is no self to be reborn. What carries over from one moment to the next is the consequences of previous actions. Fundamentally, kamma has to do with mental actions, volitions or intentions, and their results. The law of kamma is that volitional actions have consequences. Good actions have good consequences and bad actions have bad consequences. These consequences, like the actions from which they ensue, have to do with the mind: “The mind performing a deed is kamma and the subsequent mind is the result of that kamma” (Buddhadasa, 1988). The impact of good or bad deeds is first of all on the mind performing them.
Kamma is cumulative and formative, but it is not destiny. The results of past kamma do not wholly determine present kamma. Kamma is formed in the present, and this is the source of our capacity to make good or bad choices. If we are trying to live a moral life, we cultivate virtues and try to do good rather than evil, but this does not guarantee us happiness. It is not only past kamma that determines whether our circumstances in life are favorable or unfavorable; there are many other forces at work (kamma is only one of five natural laws). Hence, bad things can happen to good people.
Buddhism offers a way out of kamma, the cessation of kamma through nibhana. The arahant, the enlightened saint, who is free of all defilements, can still be affected by past kamma but no longer generates fresh kamma. The arahant acts with volition but these actions "leave no trace on the mental continuum just like the flight of a bird across the sky" (Bodhi, 2011). Prior to achieving enlightenment, the would-be arahant acted virtuously, perfecting kamma to such an extent that it could be overcome. Perfecting kamma to end kamma entails breaking the samsaric cycle of birth and death in each moment by freeing oneself from ignorance (avidya) and craving (tanha).