15 But these things perhaps you know not: you would have nothing in common with the creatures which are without you. Enter now into yourself, and from your own nature consider its Artificer. What is there to find fault with in the framing of your body? Be master of yourself, and nothing evil shall proceed from any of your members. Adam was at first without clothing in Paradise with Eve, but it was not because of his members that he deserved to be cast out. The members then are not the cause of sin, but they who use their members amiss; and the Maker thereof is wise.
Who prepared the recesses of the womb for child-bearing? Who gave life to the lifeless thing within it? Who knitted us with sinews and bones, and clothed us with skin and flesh, and, as soon as the child was born, brought streams of milk out of the breasts? How grows the babe into a boy, and the boy into a youth, and then into a man; and, still the same, passes again into an old man, while no one notices the exact change from day to day? Of the food, how is one part changed into blood, and another separated for excretion, and another part changed into flesh?
Who gives to the heart its unceasing motion? Who wisely guarded the tenderness of the eyes with the fence of the eyelids? For as to the complicated and wonderful contrivance of the eyes, the voluminous books of the physicians hardly give us explanation. Who distributes the one breath to the whole body? You see, O man, the Artificer, you see the wise Creator.
Source: Catechetical Lectures (New Advent)