Living High and Letting Die: Our Illusion of Innocence (1996)
The Preservationist holds that, to save others from suffering truly serious losses, like the loss of life or limb, often it's wrong to lie, and to cheat, and to steal, even though nobody will ever suffer much from your doing any of that. By contrast, the Liberationist holds that, when necessary to lessen serious suffering, then, provided nobody suffers seriously in consequence of your so doing, it's always morally good to do all those unruly things and more.
Here, we may well distinguish between Extreme Liberationism and Open Liberationism. So, as regards stealing, for example, the Extreme view holds that ... not only is it good to steal, but it's wrong not to do so. By contrast, Open Liberationism holds that it's at least good to steal and, while it's open to the (epistemic) possibility that it's wrong not to do so, it's also open to the possibility that it's not wrong. While I'm inclined to think that, in the end, even the Extreme view is correct, in this book it's enough to argue for Open Liberationism.