▁the ▁capital ist ▁mode ▁of ▁production . ▁He ▁reject s ▁the ▁claim ▁by ▁Eng els ▁that ▁the ▁law ▁of ▁value ▁is ▁associated ▁with ▁the ▁entire ▁history ▁of ▁economic ▁exchange ▁( tra de ), ▁and ▁modified ▁when ▁the ▁vast ▁majority ▁of ▁inputs ▁and ▁outputs ▁of ▁production ▁have ▁become ▁market ed , ▁pr iced ▁comm od ities . ▁Marx ▁himself ▁said ▁that ▁the ▁law ▁of ▁value ▁" develop s ▁fully ▁only ▁on ▁the ▁foundation ▁of ▁capital ist ▁production ", ▁imp lying ▁that ▁the ▁law ▁of ▁value ▁already ▁assert ed ▁itself ▁before ▁capital ist ▁production , ▁although ▁not ▁fully . ▁Indeed , ▁in ▁a ▁criticism ▁of ▁Adam ▁Smith , ▁Marx ▁specifically ▁refers ▁to ▁the ▁law ▁of ▁value ▁gover ning ▁" simple ▁comm od ity ▁exchange " — the ▁point ▁being ▁that ▁this ▁law ▁is ▁transformed ▁in ▁capital ist ▁exchange ▁where ▁" more ▁labour ▁is ▁ex changed ▁for ▁less ▁labour ▁( from ▁the ▁labour er ’ s ▁stand point ), ▁less ▁labour ▁is ▁ex changed ▁for ▁more ▁labour ▁( from ▁the ▁capital ist ’ s ▁stand point ) ". ▁ ▁Other ▁Marx ists ▁( including ▁Ernest ▁Mand el , ▁Michael ▁Per el man ▁and ▁the ▁Japanese ▁scholar ▁K oz o ▁Un o ) ▁followed ▁Marx ▁and ▁Eng els ▁in ▁bel ieving ▁that ▁the ▁law ▁of ▁value ▁emer ges ▁and ▁develop s ▁from ▁simple ▁exchange ▁based ▁on ▁simple ▁comm od ity ▁production . ▁If ▁the ▁law ▁of ▁value ▁was ▁unique ▁to ▁capital ism , ▁it ▁becomes ▁impossible ▁to ▁explain ▁the ▁development ▁of ▁pre - cap ital ist ▁comm