The Upaniṣads are an integral part of Vedas, they represent a branch of the primordial Tradition and constitute the essence of itself. The expression (end of the ) should be understood in the double meaning of ‘conclusion’, as the Upaniṣads are the last part of the texts, and of ‘purpose’, because what is being taught is the ultimate goal of Traditional Knowledge. The central theme of the is the quest for the Ultimate Reality, they therefore represent Metaphysics in its real sense. This type of research is not an end to itself, for the Upaniṣads represent ways of contact and tools of realization; to this end they indicate a concise and complete sequence that concedes little or nothing to the analytical mind. The five presented in this text – , , and – are commented extensively by Raphael. In his commentary, Raphael frames and broadens all the various points in the context of the traditional (Non-duality) teaching, and thus provides the western mind with the key to the comprehension of their symbolic, figurative, and analogical language.