Note that James is distinguishing between having a PhD certificate and having a level of knowledge one typically gains in pursuing a PhD. His point is that one

Note that James is distinguishing between having a PhD certificate and having a level of knowledge one typically gains in pursuing a PhD. His point is that one can have the second without the first. PhD-level expertise can be very useful, even when just teaching undergrads. My father was a PhD in organic chemistry and sometimes taught introductory organic to pre-meds. He insisted that an MS in chemistry was not sufficient to teach even undergrad organic, because diagnosing student misconceptions and lab technique required a depth of understanding you only get from extensive research work.