Individual wrote:A skeptic might ask, "So, where is this merit collected?"
If it's a materialist conception of kamma (like that of the Jains) that the skeptic is interrogating, then she's justified in asking such a question. But if it's the Buddhist conception then she's simply making a category mistake.
Correct me if I'm wrong, but puñña is also distinguished from ordinary currency in that it is not a limited commodity.
Not necessarily. Only a finite amount of merit can be accumulated in a single lifetime. Of course when multiple lives are taken into account then merit-currency does become potentially unlimited, but then so does ordinary currency when other factors are introduced (e.g. when a nation is subjected to the fiscal profligacy of a Robert Mugabe or a 1970's Labour government).
In any case, let's not push the simile too far.
How, though, can something real thus impermanent be limitlessly produced?
How couldn't it? If the round of saṃsāra is without discernible beginning then there's no limit to the number of puñña-generating wholesome cittas that might have arisen in any given continuum, nor to the number that might arise in the future.
If puñña could be limitlessly produced and puñña brings happiness, how could one even say that life is dukkha?
1. In addition to the mental factors that generate puñña, there are those that generate its opposite, pāpa, which ripens in pain.
2. Puñña can't be generated just because one wants it to be, or wants the fruits that it brings, for the conditions responsible for it are anattā, hence out of one's control.
3. Even if there were only puñña, and no pāpa, there would still be dukkha, for puñña ripens as pleasurable feeling, but even pleasurable feeling is included in the dukkha of formations.