However, as the last instances suggest to us, this unity of type, characteristic as it is of faithful developments, must not be pressed to the extent of denying all variation, nay, considerable alteration of proportion and relation, as time goes on, in the parts or aspects of an idea. Great changes in outward appearance and internal harmony occur in the instance of the animal creation itself. The fledged bird differs much from its rudimental form in the egg. The butterfly is the development, but not in any sense the image, of the grub. The whale claims a place among mammalia, though we might fancy that, as in the child's game of catscradle, some strange introsusception had been permitted, to make it so like, yet so contrary, to the animals with which it is itself classed. And, in like manner, if beasts of prey were once in paradise, and fed upon grass, they must have presented bodily phenomena very different from the structure of muscles, claws, teeth, and viscera which now fit them for a carnivorous existence. Eutychius, Patriarch of Constantinople, on his death-bed, grasped his own hand and said, "I confess that in this flesh we shall all rise again;" yet flesh and blood cannot inherit the kingdom of God, and a glorified body has attributes incompatible with its present condition on earth. 5. More subtle still and mysterious are the variations which are consistent or not inconsistent with identity in political and religious developments. The Catholic doctrine of the Holy Trinity has ever been accused by heretics of interfering with that of the Divine Unity out of which it grew, and even believers will at first sight consider that it tends to obscure it. Yet Petavius says, "I will affirm, what perhaps will surprise the reader, that that distinction of Persons which, in regard to _proprietates_ is in reality most great, is so far from disparaging the Unity and Simplicity of God that this very real distinction especially avails for the doctrine that God is One and most Simple."[174:1] Again, Arius asserted that the Second Person of the Blessed Trinity was not able to comprehend the First, whereas Eunomius's characteristic tenet was in an opposite direction, viz., that not only the Son, but that all men could comprehend God; yet no one can doubt that Eunomianism was a true development, not a corruption of Arianism.