Concentration meditation (shamatha) has nine stages of mental development starting with the mind mostly off its object. With the second stage the mind is equally on and off the object. By the third stage the mind is mostly on the object, and by the forth stage always on the object. By the fifth stage the mind is firmly on the object, and the sixth enhances mental clarity, which becomes complete on the seventh stage. On the eighth stage the mind is fully stable on the object and clear but effort to maintain this is required. On the ninth stage effort is no longer required. Full concentration with clarity happens naturally.