This was first raised by Plutarch, and it concerns a crucial issue in conservation/restoration which is how to maintain authenticity in the face of replacing worn out parts of an object or structure. The idea is, perhaps, most economically discussed in ‘Any Fools and Horses’ in the scene known as Trigger’s Broom.
Now you are ready to appreciate the philosophic issue that is discussed in this short video by the Khan Academy. Click here.