I’m using my blog to beg for help on a minor point.
The Wikipedia article on pscyhological egoism, which draws on the e Stanford Encyclopedia of Philosophy includes
Finally, psychological egoism has also been accused of using [[circular logic]]: “If a person willingly performs an act, that means he derives personal enjoyment from it; therefore, people only perform acts that give them personal enjoyment”. In particular, seemingly altruistic acts must be performed because people derive enjoyment from them, and are therefore, in reality, egoistic.. This statement is circular because its conclusion is identical to its hypothesis (it assumes that people only perform acts that give them personal enjoyment, and concludes that people only perform acts that give them personal enjoyment).
I’ve added the claim, based on memory that “This objection was made by William Hazlitt in the 19th century, and has been restated many times since then”, but Google only produces reference to a previous occasion on which I made the same claim. Can anyone point to a good citation of Hazlitt on this, or to any other versions of this argument from the 19th and 20th centuries?