The subject of this review is a 72 page introduction to a translation of thirteen Upanishads by Robert Ernest Hume. Hume's introduction is itself divided into eleven short chapters dealing with a number of important aspects of the Upanishads. Its main focus is the peculiar monism expressed in the Upanishads, particularly in the Brihad Aranyaka Upanishad.
Hume briefly discusses the place of the Upanishads in philosophy and particularly in Indian philosophy, but he quickly turns his attention to the concept of Brahma which he characterizes as "the world-ground" and "the Real of the real." This most fundamental idea is the conceptual starting point out of which all else flows. It is, however, posited as a speculative, but objective fact. In contrast to this, Hume describes the Atman or the the cosmic soul. Its character can be best understood by beginning with the multifarious, illusory world of experience. Recognizing that it comes with no guarantee of facticity, the phenomenal world is understood to be the creation of mind. Furthermore, the atman (or individual mind) also is recognized as an illusion. Through deep reflection, or the practice of yoga, one can come to understand that one's sense of self and the world are fragments of the all-embracing Atman, which in turn is no different from Brahma. Identifying the Atman with Brahma overcomes the duality of subject and object and brings one to understand the monism at the heart of reality.
It is notable that a Hume asserts that a true understanding of Brahma is not really possible and that the nearest experiences we have of it are deep sleep and death, essentially non-experience; however, by accepting this metaphysical monism, one is placed in a position to more nearly understand the fundamental truth. According to some portions of the Upanishads, simply holding this metaphysical view will cause one to live morally.
Hume points out that the views expressed in the early Upanishads are sometimes different from those of the later Upanishads and that even within a single Upanishad, important differences can be identified. The dating of the Upanishads relies to great extent on these differences and the reliability of these dates depend in turn on a theory about the progress of religious insight. It assumes that the Upanishads that are characterized by a closer affinity to the nature worship of the earlier Vedic period were written first and that those describing an abstract monism were written later. The moral components of Hinduism also are suggested to make a later appearance. These may be a very reasonable assumptions; however, they do need to be recognized as assumptions. In The Origin and Growth of Religion Max Muller makes a strong case against religion generally progressing from animism to monotheism.
In any case, monotheism certainly has become the dominant and lasting form of the Indian religious vision and its roots are in the Upanishads.