▁argument ▁in ▁Capital ▁Vol . ▁ 3 ▁is ▁that ▁there ▁is ▁a ▁constant ▁contradiction ▁in ▁capital ism ▁between ▁the ▁in es cap able ▁labour - cost s ▁in cur red ▁to ▁produce ▁products , ▁and ▁the ▁laws ▁of ▁price ▁competition ▁which ▁create ▁pressure ▁to ▁maxim ize ▁the ▁return ▁on ▁capital ▁inv ested — a ▁contradiction ▁which ▁must ▁constantly ▁be ▁medi ated ▁in ▁practice , ▁bringing ▁about ▁the ▁" real ▁movement " ▁of ▁the ▁production ▁system ▁( ide ally , ▁capital ists ▁would ▁prefer ▁just ▁to ▁trade ▁assets ▁without ▁the ▁n uis ance ▁and ▁trouble ▁of ▁h iring ▁labor , ▁but ▁the ▁assets ▁have ▁to ▁be ▁produced , ▁that ▁production ▁requires ▁labor , ▁and ▁therefore ▁that ▁labor ▁has ▁to ▁be ▁organized ▁in ▁a ▁commer cially ▁effective ▁way ). ▁ ▁The ▁only ▁way ▁to ▁trans c end ▁the ▁scientific ▁" ar bitr ar iness " ▁to ▁which ▁the ▁young ▁Marx ▁already ▁referred , ▁was ▁by ▁understanding ▁and ▁the or izing ▁the ▁dynamics ▁of ▁the ▁capital ist ▁system ▁as ▁a ▁whole , ▁integr ating ▁all ▁the ▁different ▁economic ▁forces ▁at ▁work ▁into ▁a ▁un ified , ▁coh er ent ▁theory ▁that ▁could ▁with stand ▁the ▁test ▁of ▁scientific ▁criticism . ▁Thus , ▁Marx ' s ▁value ▁theory ▁offers ▁an ▁interpretation , ▁general isation ▁or ▁explanation ▁concerning ▁the ▁" grand ▁aver ages " ▁of ▁the ▁relative ▁price ▁movements ▁of ▁products , ▁and ▁of ▁economic ▁behaviour ▁in ▁capital ist ▁production ▁as ▁a ▁social ▁system , ▁but ▁it ▁is ▁not ▁possible ▁to ▁dedu ce ▁specific ▁real ▁product - pr