both for its existence and its perfection on something extrinsic. In the words of St. Thomas: "Being considered absolutely is infinite; for it can be shared by the infinite and after an infinite manner. Therefore, if the being of anything be finite, it must be limited by something else, which is in some way its cause" (Contra gentiles, I, 43). Hence that which has being or substance in the lowest degree in the mineral kingdom must depend on the infinite being and substance, and in its littleness mirror forth the greatness of its cause, for "it is of the nature of an agent," writes the Angelic Doctor (Contra gentiles, I, 29), "that it make something like itself, since everything acts accordingly as it is in act." The vegetable kingdom reflects that life whose fullness is in the source of all life. The animal kingdom declares a sovereign intelligence, and man reveals an infinite providence. But that which is infinite being is not actually different from that which is eminently substance or which has the plenitude of life and intelligence. There is but one actual infinite (Sum. th., I, q. 7). To quote our guide, "Everything, so far as it is being, is actual and, in a manner, perfect; because every act is a certain perfection" (I, q. V, a. 3). Therefore that which has the plenitude of being has also the plenitude of every perfection, and after a manner befitting an infinite being.
This examination into the nature of the perfect leads us to consider the good, of which the perfect is the foundation. "Since the nature of goodness," writes St. Thomas, "consists in this, that one thing is capable of perfecting another as its end; everything that is of the nature of an end is also of the nature of goodness. Now, two things belong to the nature of an end; of which the first is, that it be desired, or wanted, by those things which are not as yet in possession of their end; and, secondly, that it be loved, and, as it were, lovable by such as have attained their end. For it is part of the same nature to tend toward its end and, to a certain extent, to rest in its possession" (De verit., q. XXI, a. 2). The relation of goodness to truth also illustrates the Thomistic idea of perfection, and is emphasized and defined in the following passage:
