This article investigates an apparent, convergent shift in common law jurisdictions away from the traditional principle of joint and several liability towards proportionate liability in cases involving multiple wrongdoers, and argues that this is best seen as an unprincipled drift. The shift is often presented by defendants and legislators as a logical extension of the ethics of comparative (contributory) negligence doctrine. Here we deny any ethical connection between the two doctrines. We also suggest that there is no good, generalisable ethical or pragmatic argument in favour of proportionate liability in its own right and caution jurisdictions currently considering reform of the joint and several liability rule against leaping to any such assumption.