ceiling lights

I admit I havent a clue about wiring. I just replace a light fitting by copying the wiring on the light I am replacing. I have replaced a few 3 way spotlight lights and normally it is just a case of putting the live and neutral in the same place as the old lighting. The ceiling usually has an earth wire coming down which I attach to the light frame with a securing screw. But on the new light I am putting up the live and neutral are simple but the earth from the ceiling comes down in a loop and goes back into the ceiling without touching the lighting. The new light I am putting up has an earth wire already attached to the frame. What do I do about this earth wire? Do I attach it to the earth from the ceiling ? This means of course that the old light I took down wasnt attached to the ceiling earth