religious beliefs has been greeted with a degree of skepticism by some leading economists, like greg mankiw. >> i don't think one can go straight from any sort of religious view to what an optimal tax system looks like, but in terms of fairness and what's the role for government, sure, i think all of our values come into play. >> reporter: there's no debate that tax laws should be fair, but how in a pluralistic society such as ours do we even define the word "fair"? and assuming we can define it, how far should the government go using tax dollars to promote fairness? >> the aim of tax policy is to generate economic growth. a rising tide lifts all boats. i don't think that, as a general proposition, using tax policy to create fairness or equality works. to take money from the rich, money that they have earned because they have worked hard, is not by itself just, and again, if you take money from the rich beyond a certain point you're going to create disincentives for wealth creators, and that's going to have a huge effect on the poor as well. >> reporter: one remedy championed by steve forbe