A study published last week by Massachusetts Institute of Technology economist David Autor found that even as high school graduates saw their inflation-adjusted income drop a cumulative 11 percent from 1980 to 2012, college graduates experienced a jump of 20 percent to 56 percent, depending on whether they went on to graduate school. That amounts to more than $500,000 in additional income over a college graduate’s lifetime.

These findings have revived the debate over the cost and benefits of college. Entrepreneurs such as Peter Thiel have argued that college is a waste of time and money, saddling young people with enormous debt and giving them limited practical skills. Many of the world’s wealthiest people never went to college, he claims (never mind that Thiel himself attended Stanford University and Stanford Law School).

But overlooked in all the claims and counterclaims is an obvious question: Why are Americans so obsessed with putting a price tag on the value of a college education?

A century and a half ago, it wouldn't have occurred to most prospective students to ask whether college was a worthwhile investment. People went to college as preparation for the ministry, law and other professions; they also attended as an entree into the ruling elite.

The idea of attending college in the hopes of boosting your earnings would have appeared uncouth. The few educators who even contemplated this notion tended to apologize for raising it. “Education, the true and large development of manhood,” wrote one contributor to the New Englander and Yale Review in 1888, “is so clearly of supreme worth in itself, that there is incongruity in estimating it … by a pecuniary standard.”

Indeed, most people viewed college as antithetical to business. “It is the noble service of the college," the contributor added, "to counteract the overweening mercantilism of the time and to lift society out of the mire of interests and gains.”

A critic of college writing in the same era put it more baldly: “Except a skinned eel or a boiled lobster, few things are worse prepared for the struggle of life than the average graduate.”

Reformers eager to expand higher education naturally disagreed, and in the 1880s and 1890s, they began fiercely advocating the idea that a college education would pay dividends to men -- and most were men -- contemplating careers as salaried managers. These men needed to see the big picture, educator Stephen Fellows argued in 1886. They needed “trained minds" and "disciplined intellects.”

Many business leaders scoffed at the idea, particularly those of an entrepreneurial background. From their perspective, a college degree wasn't just useless, but also downright harmful. Chicago industrialist Richard Teller Crane declared in 1903 that for “young men who have to make their own way in the business world,” colleges “are the cause of most serious error, if not of positive injury to this class of young men.”

Neither side was well positioned to prove its point, though the skeptics had the edge: College, they liked to point out, cost a good deal of money, and it wasn’t clear how dissecting Latin texts could translate into success in the business world. Moreover, every year spent in college was a year without earnings.