It would be wrong for the eye to say to the hand, “I don’t need you,” and equally wrong if the head said to the foot, “I don’t need you.”
Think of it this way. If the whole body were just an eyeball, how could it hear sounds? And if the whole body were just an ear, how could it smell different fragrances?
So now we see that there are many differing parts and functions, but one body.
In fact, the weaker our parts, the more vital and essential they are.