"Punya" or "merit" is a particular type of "karma" leading to the destruction of "karma" and the escape from "samsâra". "Karma" is conditioned action arising from a motive and seeking a result, i.e. always requiring further action. Confusion between good "karma" and merit is common. The former leads to a better rebirth (a higher one with better circumstances), whereas the intent of the latter is to cause liberation from "samsâra" by virtue of the power of the object of merit, the Three Jewels : Buddha, Dharma & Sangha. Hence, good "karma" & merit differ in terms of motivation & goal. As one of the two causes of enlightenment (the other being wisdom), it takes us beyond cyclic existence. Moreover, excellent merit is motivated by the mind of enlightenment for the sake of all sentient beings (cf. Bodhicitta).
Another form of the object of merit is the so-called "Field of Merit", the assembly of enlightened beings visualized during meditation in front of us. Ordinary (samsaric) good seeds allow us to harvest outer ordinary (samsaric) crops. But if we sow faith & the spiritual path in the Field of Merit, we harvest, besides good fortune in this and the next life, the extraordinary inner crops of Dharma realizations such as love, compassion, joy, equanimity, "Bodhicitta", physical & mental suppleness, wisdom, liberation, the irreversible escape from cyclic existence, and final enlightenment. Ordinary good "karma" can never realize this ! It does lead to the climax of the world of the gods, yet gets exhausted and so cannot take away suffering for good.
While liberation allows the Arhat to enter a personal, "lesser" type of "nirvâna", final enlightenment involves a total, complete escape from all emotional defilements and mental obscurations of "samsâra".
"Karma" or "action" is understood as a mental, verbal (energetical) or physical deed, and "vipâka" its fruit, result or reaction, accompanying every action like a shadow following its object. The seed is "karma", the fruit arising from it is "vipâka". In general, "karma" refers to actions, their effects and the potentialities left in the mind from the moment of the completion of the action to the moment they ripen and their results are experienced.
In a wider sense, every contaminated event (a phenomenon tainted by reification) is determined by "karma", the natural power of action and its consequences. Karmaless action has done away with reification. The complete network of concordant conditions giving rise to physical, psychological & social determinations is the result of past momenta. Much of what "karma" was about in the past, is today the object of science (the DNA-code as an example of "karma" ?). In a narrow sense, "karma" points to the spiritual consequences of actions and cannot be divorced from an implicit hylic pluralism, explaining how the invisible mechanisms of "karma" operates.
Any kind of physical, verbal & mental intentional action is "karma" and so generally, all good & bad actions constitute "karma". Involuntary, unintentional or unconscious actions, although deeds, do not constitute "karma", for conscious volition is absent. This differs from those non-Buddhists (like the Jains) who think unintentional actions also constitute "karma".
In the workings of "karma", mind is crucial. All physical actions, verbal & mental deeds are coloured by consciousness. Hence, when mind is guarded, bodily action is guarded and speech is also guarded.
The simple mechanism of action is given by the first two kinds of actions mentioned by the Buddha : good begets good, evil begets evil, like attracts like. A same message is heard in Ancient Egypt, in the Judeo-Christian West and in the Muslim world. This universal message is not typically Buddhist. By contrast, the notion of action destroying action points to the Truth of Cessation and the possibility of "nirvâna". This destruction cannot be complete without the end of ignorance ("avidyâ"), the fundamental root-cause of our wandering about as blind, unsatisfied, closed-up actors.
