What is the application of the penological justification argument in the context of the Eighth Amendment challenge?

The application of the penological justification argument urged by plaintiffs is a novel one. As with Eighth Amendment challenges generally, the penological justification argument has been discussed in the context of challenges to the conditions of confinement or the severity of the sentence imposed. (See id., at pp. 182-183, 96 S.Ct. at pp. 2929-2930; Coker v. Georgia, supra, 433 U.S. at pp. 591-592, 97 S.Ct. at pp. 2865-2866; Rhodes v. Chapman, supra, 452 U.S. at pp. 344-346, 101 S.Ct. at pp. 2397-2399.) The argument has not been urged as a basis for prohibiting the states from punishing certain conduct criminally. Moreover, plaintiffs cite to no cases in which a court has found incarceration or any other punishment to be so "purposeless" that it constitutes cruel and unusual punishment."