He may say with Parmenides, who, upon reading a philosophical discourse before a public assembly at Athens, and observing, that, except Plato, the whole company had left him, continued, notwithstanding, to read on, and said that Plato alone was audience enough for him.--Adam Smith
The English Bill of Rights (1689) expressly forbids ""cruel and unusual" punishment, and this found its way into the U.S. Constitution. One important, enduring argument against such punishment -- and many other forms of cruelty that may not, in fact, constitute 'punishment' -- can be found in Seneca's Letter 7: viewing and otherwise participating in the degradation and cruelty of others, even in the context of justified punishment [ille meruit ut hoc pateretur], can harm not just the victims or punished, but perpetrators and spectators alike. This is especially so if the cruelty produces pleasure as it is likely to do at public spectacles [spectaculo]* because then this pleasure makes our soul receptive; a desire for more cruelty creeps up on us [per voluptatem facilius vitia subrepunt].
Seneca's particular target is the institution of aestheticized, public spectacles of cruelty and inhumanity [crudelior et inhumanior].** He emphasizes the significance of audience participation [spectatoribus suis obiciuntur]. He reorients and subtly transforms Plato's arguments for censorship of the arts to focus on the more pernicious institutions that indirectly teach people to celebrate cruelty. Seneca's argument applies to a lot of issues that we are not likely to consider primarily in terms of political speech: mass sporting events; war coverage; disaster tourism, and any form of entertainment that rely on the pleasures derived from exposure to the suffering of others. (This is not to deny that the targets of Seneca's argument can overlap with Plato's, and that his argument is indebted to Plato's moral psychology.)