Ramana Maharshi : difference between deep sleep, laya and samadhi

Question - What is the difference between deep sleep, laya [a trancelike state in which the mind is temporarily in abeyance] and samadhi?
Ramana Maharshi : In deep sleep the mind is merged and not destroyed. That which merges reappears. It may happen in meditation also. But the mind which is destroyed cannot reappear. The yogi's aim must be to destroy it and not to sink into laya. In the peace of meditation, laya sometimes ensues but it is not enough.

It must be supplemented by other practices for destroying the mind. Some people have gone into yogic samadhi with a trifling thought and after a long time awakened in the trail of the same thought. In the meantime generations have passed in the world. Such a yogi has not destroyed his mind. The true destruction of the mind is the non-recognition of it as being apart from the Self. Even now the mind is not. Recognise it. How can you do it if not in everyday activities which go on automatically? Know that the mind promoting them is not real but is only a phantom proceeding from the Self. That is how the mind is destroyed.