"The capacity  .  .  . of human beings to inflict pain on other human beings, in the name of law, the state .  .  . is .  .  . widespread and enduring.  Torture is thus something that a public authority does or condones."

Edward Peters, Department of History, University of Pennsylvania, author of  Torture  (Philadelphia: University of Pennsylvania Press, 1985, Expanded Edition 1996) This quotation is on p. 3

Most comprehensive modern study of torture is:

Piero Fiorelli, La tortura giudiziaria nel diritto comune (2 volumes; Milan: 1953-1954)