It is not true, however, that "the want of a more appropriate word" really compels us to use the word _power_ in a passive sense. Have we not the word _potency_? This word exactly answers our purpose. It is not only the exact equivalent of the Latin _potentia_, but is also the immediate relation of the terms _potential_, _potentially_, _potentiality_, which are already admitted in common philosophical language as expressing capability, passiveness, and liability. These latter words are only subordinate members of a family, of which _potency_ is the head. Therefore, to convey the notion of _potentia passiva_, we have a more appropriate word than "power," and nothing compels us to employ the absurd expression of "passive power." On the other hand, the remarks above made, on the consequences of the promiscuous use of the word _potentia_ in the active and the passive sense, would suffice to show that the word "power," even if it could be used without absurdity in the passive sense, should, in philosophy, be restricted to the active; as it is most desirable that things which are so thoroughly opposite be expressed by different words. Thus, the word "power" retaining its active meaning, the _potentia passiva_ may very appropriately be styled "potency." Some will ask, Why should we use the word "potency" in this new sense, while we have already the term "potentiality," which seems to express very exactly the same notion? I answer that the principle of passivity, which we call "potency," is an essential constituent of created beings; whilst "potentiality" is not an essential constituent, but an attribute flowing from the essential constitution of being, on account of the potency which the latter involves. Accordingly, "potentiality" cannot stand for "potency," any more than rationality can stand for reason, or materiality for matter.