Bhagavan Sri Ramana used to say that all techniques of meditation and concentration presuppose the retention of the ego/mind. Bhagavan used to joke that employing the ego/mind to overcome the ego/mind is like hiring a thief, who is all dressed up as a policeman, to catch the thief. The policeman will pretend to make herculean efforts to catch the thief, give periodic reports of progress, but will fail each time (since the policeman is the thief!).