Acharya Prashant explains the three methods mentioned in the Manu Upanishad for realizing the Self: reasoning, listening, and self-experience. He defines reasoning as the process of questioning, demanding proof, and using logic to expose falsehood. He emphasizes that while logic may not reach the ultimate truth, it is essential for dismantling superstitions and lies. He distinguishes between proper logic used for seeking truth and 'Vitanda', which is logic used to defend ignorance or blind faith. He also highlights the importance of science in understanding the physical world, noting that spirituality begins where science ends, focusing on the observer rather than the observed object.