It works. A reader writes:
I took Mansfield's Gov 1061 on the history of modern political philosophy, and it was without a doubt the most rewarding experience of my undergraduate career. After receiving a C+ on my first paper after I'd turned in the usual, formulaic BS I had for most other classes, I actually applied myself. And when I got A-s on the next two papers, I was never more proud of what I'd achieved.
Going into a class knowing that a professor is a notoriously hard grader weeds out many of the grade-obsessed careerists who overwhelmingly populate Harvard - a refreshing experience to say the least. It puts the focus more squarely on actually engaging with ideas and getting something out of the material. And it certainly doesn't hurt to get to listen to Mansfield describe sotto voce the philosophy of Machiavelli, punctuating his points with a closed fist pound of the podium.
I miss those days.