Mahabharata 10.3.9

10.3.9

yathā hi vaidyaḥ kuśalo jñātvā vyādhiṃ yathāvidhi |
bheṣajaṃ kurute yogātpraśamārthamihābhibho || 9 ||

As a skilful physician, having duly diagnosed a disease, prescribes a medicine by the application of his intelligence for effecting a cure, even so men, for the accomplishment of their acts, use their intelligence, aided by their own wisdom. What they do is again disapproved by others. A man, in youth, is affected by one kind of understanding. In middle age, the same does not prevail with him, and in the period of decay, a different kind of understanding becomes agreeable to him. When fallen into terrible distress or when visited by great prosperity, the understanding of a person, O chief of the Bhojas, is seen to be much afflicted. In one and the same person, through want of wisdom, the understanding becomes different at different times. That understanding which at one time is acceptable becomes the reverse of that at another time.