Montesquieu
 

XXI.4 The principal difference between the commerce of the Ancients and that of today

From time to time the world puts itself into situa­tions that change com­merce. Today the com­merce of Europe is prin­ci­pally car­ried on from north to south. At this time the dif­fe­rence of cli­ma­tes cau­ses the peo­ples to have great need of each other’s pro­ducts. For exam­ple, beve­ra­ges ship­ped from south to north make up a kind of trade that was unk­nown to the Ancients. Thus the capa­city of sea­going ves­sels, which once was mea­su­red by quan­ti­ties of grain, is now mea­su­red in bar­rels of liquids.

The ancient com­merce that we know about, taking place bet­ween one Mediterranean port and ano­ther, was almost all in the south. Now, peo­ples of the same cli­mate, having more or less the same things at home, have less need of trade amongst them­sel­ves than with those of a dif­fe­rent cli­mate. Trade in Europe was the­re­fore for­merly less exten­sive than it is today.

This does not contra­dict what I have said about our trade in the Indies : exces­sive dif­fe­rence of cli­mate makes their rela­tive needs nonexis­tent.