A new (to me) way of using act/potency distinction to criticize pre-Socratics

De Generationibus Book I, chapter 9 makes an interesting claim (if read it correctly and remember correctly what I read).  It argues against the pro-Socratics on the basis that they could not explain efficient causality, i.e., the action/passion relation, precisely because they don't make the distinction between act/potency.