Burnside proved, by use of character theory, that if a finite group $G$ has a conjugacy class $C$ such that $\vert C \vert$ is a prime power $> 1$, then $G$ is not simple. Let us call this statement "Burnside's non-simplicity theorem".
From this theorem, Burnside deduced easily his "$p^{a}q^{b}$ theorem" : every finite group whose order has at most two distinct prime factors is solvable.
It is well known that Burnside's $p^{a}q^{b}$ theorem can be proved indepedently from character theory. Can "Burnside's non-simplicity theorem" also be proved indepedently from character theory ?