Sentence:  ‘if we are ourselves valets, there shall ‘exist no hero for us; we shall not know the hero when we see him;' - we shall take the <WSD>quack</WSD> for a hero; and cry, audibly through all ballot-boxes and machinery whatsoever, Thou art he; be thou King over us! 
Meaning of the word marked with <WSD> tags:  (doctor) A fraudulent healer or incompetent professional; especially, a doctor of medicine who makes false diagnoses or inappropriate treatment; an impostor who claims to have qualifications to practice medicine. (from "c." 1630)