  In his recently published article [1], P.M. Stevenson has claimed that the
"principle of maximum conformality (PMC) is ineffective and does nothing to
resolve the renormalization-scheme-dependence problem", concluding that the
successes of PMC predictions is due to the fact that the PMC is a "laborious,
ad hoc, back-door" version of the principle of minimum sensitivity (PMS). We
point out that these conclusions are incorrect, being drawn from a
misunderstanding of the PMC and the overestimation of the PMS. The purpose of
the PMC is to achieve precise fixed-order pQCD predictions, free from
conventional renormalization-scheme and -scale ambiguities. We have
demonstrated that the PMC predictions satisfy all the self-consistency
conditions of the renormalization group and standard renormalization-group
invariance; the PMC prediction is thus independent of any initial choice of
renormalization scheme and scale. Such scheme independence is also ensured by
the commensurate scale relations among different observables. In the $N_C\to 0$
Abelian limit the PMC method reduces to the well-known Gell-Mann--Low method
for precision calculations in Abelian QED. Owing to the elimination of the
factorially divergent renormalon terms, the PMC series generally has better
convergence behavior than the conventional series, can substantially suppress
any residual scale dependence due to unknown higher-order terms, and thus
provides a reliable basis for estimating the contributions of the unknown
higher-order terms. The full Abstract and detailed explanations are given in
the body of the text.
