Is there a retribution gap? In an interesting and carefully argued paper John Danaher argues that in respect of robots, there is.

For human beings in normal life he argues that a fairly broad conception of responsibility works OK. Often enough we don’t even need to distinguish between causal and moral responsibility, let alone worrying about the six or more different types identified by hair-splitting philosophers.

However, in the case of autonomous robots the sharing out of responsibility gets more difficult. Is the manufacturer, the programmer, or the user of the bot responsible for everything it does, or does the bot properly shoulder the blame for its own decisions? Danaher thinks that gaps may arise, cases in which we can blame neither the humans involved nor the bot. In these instances we need to draw some finer distinctions than usual, and in particular we need to separate the idea of liability into compensation liability on one hand and and retributive liability on the other. The distinction is essentially that between who pays for the damage and who goes to jail; typically the difference between matters dealt with in civil and criminal courts. The gap arises because for liability we normally require that the harm must have been reasonably foreseeable. However, the behaviour of autonomous robots may not be predictable either by their designers or users on the one hand, or by the bots themselves on the other.

In the case of compensation liability Danaher thinks things can be patched up fairly readily through the use of strict and vicarious liability. These forms of liability, already well established in legal practice, give up some of the usual requirements and make people responsible for things they could not have been expected to foresee or guard against. I don’t think the principles of strict liability are philosophically uncontroversial, but they are legally established and it is at least clear that applying them to robot cases does not introduce any new issues. Danaher sees a worse problem in the case of retribution, where there is no corresponding looser concept of responsibility, and hence, no-one who can be punished.

Do we, in fact, need to punish anyone? Danaher rightly says that retribution is one of the fundamental principles behind punishment in most if not all human societies, and is upheld by many philosophers. Many, perhaps, but my impression is that the majority of moral philosophers and lay opinion actually see some difficulty in justifying retribution. Its psychological and sociological roots are strong, but the philosophical case is much more debatable. For myself I think a principle of retribution can be upheld , but it is by no means as clear or as well supported as the principle of deterrence, for example. So many people might be perfectly comfortable with a retributive gap in this area.

What about scapegoating – punishing someone who wasn’t really responsible for the crime? Couldn’t we use that to patch up the gap?  Danaher mentions it in passing, but treats it as something whose unacceptability is too obvious to need examination. I think, though, that in many ways it is the natural counterpart to the strict and vicarious liability he endorses for the purposes of compensation. Why don’t we just blame the manufacturer anyway – or the bot (Danaher describes Basil Fawlty’s memorable thrashing of his unco-operative car)?

How can you punish a bot though? It probably feels no pain or disappointment, it doesn’t mind being locked up or even switched off and destroyed. There does seem to be a strange gap if we have an entity which is capable of making complex autonomous decisions, but doesn’t really care about anything. Some might argue that in order to make truly autonomous decisions the bot must be engaged to a degree that makes the crushing of its hopes and projects a genuine punishment, but I doubt it. Even as a caring human being it seems quite easy to imagine working for an organisation on whose behalf you make complex decisions, but without ultimately caring whether things go well or not (perhaps even enjoying a certain schadenfreude in the event of disaster). How much less is a bot going to be bothered?

In that respect I think there might really be a punitive gap that we ought to learn to live with; but I expect the more likely outcome in practice is that the human most closely linked to disaster will carry the case regardless of strict culpability.