Why is punishment imposed and how do we justify the penalties imposed? ‘Why punish … and how?’ outlines the legal justifications for punishment: one perspective focuses on the crime and its seriousness; the second relates to crime prevention. Sentencing therefore looks in two directions: backwards, to assess the seriousness of the harm caused and to hold the offender accountable for that harm; and forwards to assess the risk the offender may pose to society. Sentencing objectives include proportionality, deterrence, and rehabilitation, but how do courts decide which objective is appropriate? Sentencing guidelines, mitigating and aggravating factors, and sentencing options (imprisonment, fines, and community orders) are also discussed.