Acharya Prashant explains the profound meaning of the Shanti Mantra, focusing on the concepts of 'this' and 'that' as representations of duality within the mind. He asserts that 'this' and 'that' cannot pertain to anything beyond the mind, as the mind naturally operates in pairs of opposites like pleasure and pain or cause and effect. The fundamental human sense of incompleteness arises because the mind typically focuses on only one end of duality at a time, forgetting the other. True peace and fullness are realized only when both ends are looked at together, leading to the understanding that both are 'full' or, conversely, both are 'meaningless.' He emphasizes that emptiness is a prerequisite to fullness. To experience the ultimate truth, one must negate the appearances of the world and the meanings assigned to them. Acharya Prashant clarifies that fullness is not a concept to be achieved or a thought to be pursued; rather, it is what remains when the mind is emptied of its fake fullness, ideas, and conditionings. He argues that a person's primary responsibility is to keep themselves clean of all chases, including the chase for liberation or peace, as these are just further movements of the mind. Fullness is an existential reality that expresses itself spontaneously, not a happening that occurs within the constraints of time. Finally, the speaker discusses the significance of 'Om Shanti Shanti Shanti,' explaining that peace is not a state of mind but the silence that remains when the mind and its dualities dissolve. He points out that as long as one maintains boundaries, attachments, and 'near ones,' one is condemned to have enemies and fear, because these opposites always go together. True non-duality and peace require the removal of all boundaries. He concludes by warning against interpreting 'this' and 'that' as the universe and Brahman, stating that in the presence of the ultimate truth, no 'this' remains, and all duality is transcended.