Many such critics also demand a new wealth tax on previously earned income that's been saved and invested. But what's a "fair share?" Why is 70 percent the right and proper tax take? Why not 50 percent? Is today's top rate of 35 percent inherently fair? Why not 10 percent?

Ask anyone who's willing to define or defend "fair share" in this context — whether a tax expert, an editorialist, or a neighbor — and you'll likely hear not hard facts and solid logic but a host of banal attitudes and platitudes. "Inequality is unjust!" Why? "Because it's unfair!" Why? "Because so many people are in need today — and most people agree with me." But why assume the status of needy or less rich people is caused by the rich? It just doesn't follow. If the rich aren't blameworthy for the poor lot of others, as a criminal would be for robbing and impoverishing a victim, what, in plain justice, could justify punitive taxation of the rich?