Expressivist Punishment: A First Cut
There are many candidate-bases for liability to punishment. To name but a few, according to so-called desert retributivism, W is liable to punishment because he deserves to be punished and people should get what they deserve. According to fair-play retributivism, by violating V’s rights, W breaches rules of social cooperation from which he himself benefits (in the sense that the fact that other people do not violate his rights makes it easier for him to go about his life, including his wrongful endeavours); punishing him is a way to cancel out the unfair advantage which W has thereby gained. There are many other kinds of retributivism—all of which have it in common that they regard punishment as backward-looking: whatever good it brings about, punishment is justified solely by reference to W’s wrongdoing. By contrast, deterrence or protection theories justify punishment by appealing to forward-looking considerations. W is liable to punishment, on those views, only if punishing him serves to protect other people from rights-violations at his hands, or only if it serves to deter putative wrongdoers from committing similar crimes. Pace an often-rehearsed objection to deterrence-based justifications, the latter need not deny that W is liable to punishment only if he has committed a serious wrongdoing. Pace retributivists, however, they insist that committing a serious wrongdoing is not, on its own, a basis for liability to punishment, and that it must be supplemented by forward-looking considerations. Note also that hybrid justifications for punishment can be constructed out of both retributivist and protection-based (or protectivist) arguments. One can conceivably hold, for example, that W is liable to punishment only in so far as he deserves it or has gained an unfair advantage by violating V’s rights, and that punishing him is all things considered morally justified only if it also serves protective ends.
With retributivists and some protectivists, I believe that W’s wrongdoing is the basis for his liability to punishment (modulo considerations to do with his frame of mind when acting wrongly, as we shall see in s.7.2.2)—though I do not think that desert or fair play are particularly promising justificatory routes. With protective theories, however, I also believe that all-things-considered justifications for punishment must attend to forward-looking considerations. Let me elaborate. By violating V’s rights, W has forfeited his right not to incur the very specific kind of burden which punishment, as distinct from compensatory or indeed defensive harms, constitutes. Granted, all three kinds of harm imposition are responses to W’s wrongdoings. Unlike the imposition of compensatory and defensive harm, however, punishment has an inherently expressive dimension: that is, it expresses the view that by violating V’s rights, W has treated her as less than his moral equal whereas in fact she is and always was entitled to be treated by him as such; it also expresses the view that W’s conduct was not of the kind one can expect of a rational and moral agent. Imposing such a harm is justified, in turn, by the importance of explicitly communicating that there always was moral parity between W and V. Failure to sanction W’s wrongdoing is on the one hand a failure to take V’s rights seriously and on the other hand a failure to regard W as the moral and rational agent he is. Merely disapproving of W openly will not do, for it will not adequately express to V, or indeed to W and all and sundry, that W acted grievously wrongly by violating V’s rights. Harming W, by contrast, does express that point, in that it reaffirms V’s moral status as well as his. 
Crucially, the expressive value of punishment does not lie in the fact that punishment often expresses anger, repugnance, and disgust at what offenders did. However understandable or even justified those emotions might be, expressing them through our punitive practices is likely to increase the risks that offenders, alienated as they will be made to feel, will reoffend and harm their prospects of rehabilitation. It is also likely to detract attention from victims for the sake of debasing perpetrators. This is particularly problematic, because expressing commitment to victims’ moral standing is as important as communicating the extent to which perpetrators did do wrong. In addition, offenders, though unquestionably responsible for their acts, nevertheless often act under less than ideal agential and epistemic circumstances, suffering as many do of various psychological disorders. Our reactive attitude to their wrongdoings ought to reflect both the fact that they did commit grievous wrongdoings and the fact that there were non-trivial obstacles to their desisting from so acting. As Nicola Lacey and Hanna Pickard persuasively argue, we may, indeed should, deem them blameworthy, but in a detached way that recognizes that they are responsible for their actions (failing which we culpably show lack of respect for their agency), and not in an affective way which overlooks the conditions under which they acted (as a result of which we culpably show lack of compassion for their humanity, and risk imposing on them punishment which would neither fit nor be proportionate to the crime).5
To recapitulate briefly, W is liable to be punished to the extent that and only if he has committed a grievous wrongdoing, as a way to communicate to him, as well as to all and sundry, the magnitude of his wrongdoing. As we saw above, however, it does not follow from the claim that W is liable to punishment that he may justifiably be punished all things considered. Advocates of forward-looking theories of punishment hold that punishing W is all-things-considered justified only if it serves some future good—such as protecting third parties either from W’s reoffending or from other putative wrongdoers, or such as rehabilitating W into the community. I agree, particularly in so far as punishment involves the deployment of considerable resources which could be directed to other ends. Thus, we may not punish W if, as a result, he would commit further and equally serious or worse wrongdoings, or if others would so act. Nor may we punish him if the harms incurred by third parties as a result either of the punishment itself or of the operation of the judicial system are disproportionate relative to the value of expressing our condemnation of W’s wrongdoing and affirming V’s dignity.
-  For a classic typology of retributivist theories, see J. Cottingham, ‘Varieties of Retribution’, ThePhilosophical Quarterly 29 (1979): 238—46. For a classic retributivist account of punishment, seeM. S. Moore, A Theory of the Criminal Law (Oxford: Oxford University Press, 2010), ch. 3. For standard criticisms of retributivism, see, e.g., D. Dolinko, ‘Some Thoughts About Retributivism’, Ethics101 (1991): 537—59; R. Shafer-Landau, ‘The Failure of Retributivism’, Philosophical Studies: AnInternational Journal for Philosophy in the Analytic Tradition 82 (1996): 289—316. The locus classicus for protective theories in contemporary discussions is W. Quinn, ‘The Right toThreaten and the Right to Punish’, Philosophy & Public Affairs 14 (1985): 327—73. To my mind, thebest articulation and defence of protectivism is V Tadros, The Ends of Harm: The Moral Foundations ofCriminal Law (Oxford: Oxford University Press, 2011).
-  The justification for punishment which I develop in this paragraph is best described as an expressive interpretation of the forfeiture view. For defences of the forfeiture view to which much of whatfollows owes, see A. H. Goldman, ‘The Paradox of Punishment’, Philosophy & Public Affairs 9 (1979):42—58; C. H. Wellman, ‘The Rights Forfeiture Theory of Punishment’, Ethics 122 (2012): 371—93.Prominent communicative, or expressive, theories of punishment are: see R. A. Duff, Punishment,Communication, and Community (Oxford: Oxford University Press, 2001); J. Feinberg, ‘The ExpressiveFunction of Punishment’, The Monist 49 (1965): 397^23; A. von Hirsch, Censure and Sanctions(Oxford: Oxford University Press, 1993), esp. ch. 2; J. Hampton, ‘The Moral Education Theory ofPunishment’, Philosophy & Public Affairs 13 (1984): 208—38. Hampton herself articulates, better thananyone I can think of, the view that punishment expresses a commitment to V’s and O’s moral paritybefore the wrondgoing, and is constrained by respect for the enduring dignity of the offender. See hercontribution to J. Hampton and J. G. Murphy, Forgiveness and Mercy (Cambridge: CambridgeUniversity Press, 1988), esp. ch. 5. For a contemporary defence of the view that a failure to punish Wis a failure to treat him with respect, see C. Bennett, The Apology Ritual (Cambridge: CambridgeUniversity Press, 2008). Finally, for an interesting critique of expressivist (or communicative) theories,see Tadros, The Ends of Harm, ch. 5.
-  Broadly, Lacey and Pickard’s point is that clinical attributions of responsibility (which requires ofthe clinician that she treat patients with respect and compassion at the same time as she holds themaccountable for their wrongdoings) can usefully be imported into the penal world. See N. Lacey andH. Pickard, ‘From the Consulting Room to the Court Room? Taking the Clinical Model ofResponsibility Without Blame into the Legal Realm’, Oxford JournalofLegalStudies 33 (2013): 1—29.The view that punishing is a way to mark respect for offenders’ agency is developed by H. Morris,‘Persons and Punishment’, The Monist 52 (1968): 475—501.