That which cannot be fully understood. In one sense nothing is totally comprehensible by humans since they are not the first cause of anything. But, properly speaking, only God is said to be incomprehensible because only he is infinitely perfect and no finite mind can exhaustively understand the infinite. The Church teaches that God is incomprehensible (Denzinger 800). However, there is a difference between his incomprehensibility on earth and in heaven. On earth God is incomprehensible because he known only by faith; in heaven he is still incomprehensible because he is infinite, even though in the beatific vision we shall see him in his essence as he is. Although not comprehensible, God is not unintelligible. He can be known, here by faith and hereafter by sight. But neither on earth nor in heaven can he be totally known in the fullness of his own comprehensive knowledge of himself. "God whose Being is infinite, is infinitely knowable. No created understanding can, however, know God in an infinite manner" (St. Thomas Aquinas, Summa Theologica, I, 12, 7).