The error arises from failing to distinguish sharply between intuition and reflection. In intuition the principal and primary actor is the intelligible object. In reflection it is the intellective subject; in the intuitive order the object presents itself as it is, with its own characteristics; in the reflective order it is represented with the limitations and characteristics of the thinking subject. As the subject is limited, its conceptions are limited, and represent the infinite not as infinite, but as the not-finite; and it is in the reflective order, if we operate on our conceptions, instead of our intuitions, only by a discursive process that we can come to the conclusion that the not-finite is the infinite. The author not distinguishing the two orders, and taking conceptions which belong to the reflective order as if they belonged to the intuitive order, supposes that we may have valid conceptions beyond the sphere of intuition. But a little reflection should have taught him that, if he had no intuition, he could have no conception of the infinite.
Following St. Thomas and all philosophers of the first order, the author very properly maintains that it is by the divine intelligibility, or the divine light, that the human mind sees whatever it does see; but he shrinks from saying that we have intuition of God himself. So far as we are to understand intuition of God as intuition, or open vision of him as he is in himself, he is undoubtedly right. But objects are intelligible only in the light of God, and it is only by this light that we apprehend them. Do we ever apprehend objects by the light of God without apprehending the light which renders them apprehensible? In apprehending the object, we apprehend first of all the light which is the medium of its apprehension. The light of God is God, and if we have intuition of the light, we must have intuition of him who is the true light that "enlighteneth every man coming into this world." We cannot see God as he is in himself, not because he is not intelligible in himself, but because of the excess of his light, which dazzles and blinds our eyes through their weakness. So, very few of us can look steadily in the face of the sun without being dazzled, yet not therefore is it to be said we cannot and do not see the sun.