Montesquieu
 

XVII.2 The difference among peoples with respect to courage

We have already said that intense heat ener­va­ted men’s strength and cou­rage, and that in cold cli­ma­tes a cer­tain strength of body and mind made men capa­ble of exten­ded, hard, great, and daring acts. We observe this not only from one nation to ano­ther, but also bet­ween dif­fe­rent parts of a sin­gle coun­try. The nor­thern peo­ples of China are more cou­ra­geous than those in the south1 the peo­ples of sou­thern Korea are not as cou­ra­geous as those of the north.2

We should the­re­fore not be sur­pri­sed that the fee­ble­ness of peo­ples of warm cli­ma­tes has almost always made sla­ves of them, and the cou­rage of peo­ples of cold cli­ma­tes has kept them free. That is an effect that deri­ves from its natu­ral cause.

It was also found to be true in America : the des­po­tic empi­res of Mexico and Peru were near the equa­tor, and almost all the small and free peo­ples were and still are nea­rer to the poles.

Father du Halde, vol. I, p. 112.

Chinese books say it thus (ibid., vol. IV, p. 448).