as on Ordinarily the Understanding is a man's Soul. When the Understanding, by itself, forms ideas (of objects) within itself, it is then called Mind.
बुद्धिरात्मा मनुष्यस्य बुद्धिरेवात्मनाऽऽत्मनि। यदा विकुरुते भावं तदा भवति सा मनः॥