I’m currently working on a paper on utilitarianism before Bentham. It led me to go back to Sidgwick’s Outlines of the History of Ethics where I saw this sentence: “For the century and a half that intervenes between Hobbes and Bentham the development of English ethics proceeds without receiving any material influence from foreign sources.” I think this is largely true, but I’d love to hear some candidates for most influential foreigner (I’m assuming that Sidgwick is including Scotland in “English ethics”).
My candidate would probably be Pufendorf. His version of Protestant natural law seems to be the most influential, and (with lots of qualifications) natural law is the default moral view in the period.
Two other possibilities, both of which might involve a bit of cheating: Cicero and Mandeville. Even if you demand I count Mandeville as an Englishman (of dubious moral character…), would Mandeville’s importance enable us to make a case for a variety of French moralists (e.g. La Rochefoucauld, Pascal, Bayle)?
Any other answers, serious or playful?