You can reasonably make the intellectual journey from thinking it's permissible to eat shrimp to thinking it's not permissible, or vice versa, whereas our slavery journey was uni-directional. We are as certain we are not going back to that old kind of slavery as we are that we aren't going back to the geocentric universe.

We have to gamble, and sometimes lose as George Ainslie argues; this keeps the appetite for life sharp.

There's Hobbes, who understood in the 1640s that the sovereign is not an appointee of God, or even a figure of superior virtue and wisdom, but just a functional device whose role is to keep people from hurting and killing each other.

Atomism had no absolute 'above' and 'below' and no such rulers, so favoured the undersranding of justice as an agreement amongst equals.

Claims like 'Slavery is wrong' are not fully common-sensical, so they must be at least partly theoretical.

We need grief as a precursor to emotional refreshment, and so consume it vicariously in somewhat titrated but powerful enough form through engagement with the arts.

Epicurus was not at all interested in what we would call the problems of mass society, and he thought civic politics was just trouble and to be avoided by the wise.