This assertion is categorically false. Had the two kinds of knowledge and the two kinds of power truly been identical, then whatever is possible for one would be possible for the other, whatever is impossible for one would be impossible for the other, and whatever must pertain to one would have to pertain to the other. If such parity could be claimed for knowledge and power, it could likewise be claimed for life, hearing, sight, speech, will, and every other attribute.
Moreover, if that were admissible for the attributes, it would be admissible for the essences as well. The relation of the Lord’s knowledge to His Essence is like the relation of the servant’s knowledge to his essence: there are two knowledges and two knowers. Thus, if one may say that knowledge is like knowledge save for the distinction between eternality and origination, one could equally say that the knower is like the knower save for that same distinction.
The absurdity of this is self-evident, and its falsity can be shown in several ways. One of them is that, were the two essences identical, one could not be characterized by contingency while the other is characterized by eternality. What necessitates the Lord’s pre-existence is His very Essence; He needs nothing outside Himself for His eternality to hold. Likewise, what necessitates that the servant is dependent on a creator is his very essence; his need is not derived from anything external to him. Now, if two identical things must share whatever is possible for either of them, yet this essence cannot possibly be eternal—indeed, eternality is impossible for it—whereas that essence must be eternal and can never pass into non-existence, then their identity is impossible. And once the essences cannot be identical, their attributes cannot be identical either, for every attribute accords with the reality of its possessor.
Someone might object: “Different entities can share identical concomitants; a human being and a horse, for example, are both animals.” We reply: the generic animality that pertains to a human being is not, in every respect, identical to the animality that pertains to a horse; each differs in keeping with the difference between the two underlying realities.