Acharya Prashant explains the spiritual progression outlined in the Adhyatmopnishad, focusing on the stages of hearing, thinking, meditation, and concentration (samadhi). He clarifies that hearing is the initial physical and sensual reception of a message. This is followed by thinking, which involves critically examining the heard input using reason, logic, and the law of cause and effect to determine its credibility. Once a sentence about the truth is found reasonable and indubitable, it leads to meditation, which is the exclusive attention of the mind on that truth. He emphasizes that pursuing truth is a total enterprise requiring all of one's resources; even a small distraction can abort the pursuit because truth demands everything, whereas mediocre interests survive on very little. As the seeker progresses, the mind moves toward concentration, which Acharya Prashant identifies as samadhi. In this state, the duality between the meditator and the object of meditation dissolves. The ego, initially defined by a thousand worldly relationships, eventually sheds them until only one relationship with the truth remains. Finally, even this single relationship culminates in union, where the distinction between the subject and the object disappears, and the seeker realizes their identity as the truth itself. He describes intelligence as the fundamental nature that enables one to see clearly, reducing mental clutter and leading to the settlement of the mind.