Ethics and warmth

I just found this quotation from David Hume:

“it is only from the selfishness and confined generosity of men, along with the scanty provision nature has made for his wants, that justice derives its origin.”

Scanty provision, eh? Is this why so many ethicists come from the barren northern climes*, and rather fewer from Hawaii and other places where nature’s provision is less scanty?

*Descartes, for instance, used to withdraw to the interior of a large oven to work in warmth; Diogenes (who came from balmier latitudes, but lived in a barrel) was once asked by Alexander the Great whether the latter could do anything for him – “Yes”, said the philosopher… “get out of my sunlight”.