When an eagle is soaring in the sky, it maintains a smooth glide simply by occasionally shifting the angle of its wings. It never adjusts its flight in a violent or frantic manner, but applies only as much effort as is required. Similarly, when training in meditation, we should employ just the right amount of effort to keep our concentration balanced. If we use too much effort, we will experience distraction, but if we use too little, we will succumb to mental sinking.