(FORTUNE Magazine) – We happened to be reading up on Claiborne Pell's ideology (see the lead item) on the same day we came across The Common Good: Social Welfare and the American Future, the latest broadside of the Ford Foundation, and count ourselves lucky to have made it to cocktail time without a hives reaction. If anything, the Fordites are worse than our most liberal Senator. They plainly share his ideological perspective, down to and including support for the minimum wage, about which they repeat the crazy argument that you can't support a family on it; but they let fly with one proposal that even Pell would never buy. The proposal comes near the end of The Common Good, where they are explaining how to pay for the avalanche of social programs explicated thus far. Heart of their revenue proposal: Tax certain Social Security benefits. Which ones? ''We recommend the complete taxation of . . . benefits that exceed lifetime contributions . . . For example, if a worker contributed $100,000 to Social Security during his or her lifetime, any benefits received in excess of that amount would be . . . taxable income.'' The proposal seems weird, in part because of the factual loopiness of the example. (A worker retiring nowadays after a lifetime of paying Social Security taxes at the maximum would have paid out a total of less than $40,000.) Furthermore, the proposal does not include price adjustment. So your lifetime contributions would be counted at only about two-thirds of their value in today's prices -- and you would be paying taxes long before you had recovered your contributions. This is called soaking the nonpoor, a practice now out of favor in Congress, and raises the question of which is our most liberal foundation. It could make for a real tough puzzle.