The historian Peter Gay described "Discipline and Punish" as the key text by Foucault that has influenced scholarship on the theory and practice of 19th century prisons. Though Gay wrote that Foucault "breathed fresh air into the history of penology and severely damaged, without wholly discrediting, traditional Whig optimism about the humanization of penitentiaries as one long success story", he nevertheless gave a negative assessment of Foucault's work, endorsing the critical view of Gordon Wright in his 1983 book "Between the Guillotine and Liberty: Two Centuries of the Crime Problem in France". Gay concluded that Foucault and his followers overstate the extent to which keeping "the masses quiet" motivates those in power, thereby underestimating factors such as "contingency, complexity, the sheer anxiety or stupidity of power holders", or their authentic idealism.