[nnntrn]

In the following sentence, he does imply that it's impossible.

The 2011 NSF survey reports that 51% of humanities PhD graduates hold no degree-related debt, and that only 22% fund their degrees through their own resources. Compared to life/physical science students, more humanities PhDs fund their degrees by going into debt (by about 25%), but the majority of humanities PhDs graduate without debt and fund their degrees through fellowship grants and assisstantship positions, just like graduate students in STEM fields.

Anecdotally, all the humanities departments I am familiar with fund the vast majority (90%+) of their doctoral students.

http://www.nsf.gov/statistics/sed/digest/2011/theme4.cfm#4