It is an analysis of the social and theoretical mechanisms behind the changes that occurred in Western penal systems during the modern age based on historical documents from France.

Prison is used by the "disciplines" – new technological powers that can also be found, according to Foucault, in places such as schools, hospitals, and military barracks.

[1] Foucault begins by contrasting two forms of penalty: the violent and chaotic public torture of Robert-François Damiens, who was convicted of attempted regicide in the mid-18th century, and the highly regimented daily schedule for inmates from an early 19th-century prison (Mettray).

[2] He believes that the question of the nature of these changes is best asked by assuming that they were not used to create a more humanitarian penal system, nor to more exactly punish or rehabilitate, but as part of a continuing trajectory of subjection.

"[3]: 30  The problem for Foucault is in some sense a theoretical modelling which posits a soul, an identity (the use of soul being fortunate since "identity" or "name" would not properly express the method of subjection—e.g., if mere materiality were used as a way of tracking individuals then the method of punishment would not have switched from torture to psychiatry) which allows a whole materiality of prison to develop.

He argues that the public spectacle of torture and execution was a theatrical forum, the original intentions of which eventually produced several unintended consequences.

Foucault stresses the exactitude with which torture is carried out, and describes an extensive legal framework in which it operates to achieve specific purposes.

It also made the body of the condemned man the place where the vengeance of the sovereign was applied, the anchoring point for a manifestation of power, an opportunity of affirming the dissymmetry of forces.

The sovereign was not concerned with demonstrating the ground for the enforcement of its laws, but of identifying enemies and attacking them, the power of which was renewed by the ritual of investigation and the ceremony of public torture.

Torture was made public in order to create fear in the people, and to force them to participate in the method of control by agreeing with its verdicts.

But problems arose in cases in which the people through their actions disagreed with the sovereign, by heroizing the victim (admiring the courage in facing death) or in moving to physically free the criminal or to redistribute the effects of the strategically deployed power.

He argues that reformists were unhappy with the unpredictable, unevenly distributed nature of the violence the sovereign would inflict on the convict.

The emergence of prison as the form of punishment for every crime grew out of the development of discipline in the 18th and 19th centuries, according to Foucault.

The individuality that discipline constructs (for the bodies it controls) has four characteristics, namely it makes individuality which is: Foucault suggests this individuality can be implemented in systems that are officially egalitarian, but use discipline to construct non-egalitarian power relations: Foucault's argument is that discipline creates "docile bodies", ideal for the new economics, politics and warfare of the modern industrial age – bodies that function in factories, ordered military regiments, and school classrooms.

Prison is one part of a vast network, including schools, military institutions, hospitals, and factories, which build a panoptic society for its members.

Moreover, they showed the body of knowledge being developed about the prisoners, the creation of the "delinquent" class, and the disciplinary careers emerging.

[5]: 149 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.

Discipline and Punish consistently proposes an explanation in terms of power—sometimes in the absence of any supporting evidence—where other historians would see a need for other factors and considerations to be brought into account.