Justifications of punishment divide into those looking forward — deterrence, incapacitation, rehabilitation — and those looking back to what the offender deserves, and the practical systems built on each have converged in an unedifying way. Purely forward-looking justifications, taken seriously, license punishing the innocent wherever the effect on others would be sufficient, which almost nobody will accept; purely backward-looking ones license severity without limit provided it is deserved, which almost nobody will accept either. Every functioning system therefore uses desert to set an upper bound and consequences to determine what happens within it, an arrangement that is philosophically inelegant and works tolerably. The literature has spent considerably more effort defending the pure positions than examining the mixed one that everybody actually operates. Mixed arrangements are harder to defend in print and considerably easier to live under.