How to Make the Mind Consciousness Contemplate in a Deep and Clear Manner

Under what circumstances can the thinking function of the mind consciousness be brought into fullest play, so that deliberation is at its best and clearest? When the mind consciousness takes only one dharma as its object, or takes one dharma as the main object while engaging two or three dharmas, and moves from distraction toward focus, its deliberation is at its clearest—this is the effect of meditative concentration (samādhi). When distracted, the mind consciousness's power of deliberation is weak and its train of thought unclear. When concentration is too deep, the mind consciousness cannot move, mental activity ceases, and deliberation becomes very laborious. Only when there is concentration, yet the concentration is not excessively deep, can the mind consciousness deliberate in a way that is deep, subtle, and clear, with an open and expansive train of thought.