Interpretation of the Upanishad statements continues till date and offers new insights, though the texts belong to a time that goes far beyond what is available as recorded history. This is because they speak of matters relevant for all times and are storehouses of the awareness of eternal truth that the ancient sages steeped in meditation have discovered. Their discoveries have tried to fulfil the emotional, intelligent and intellectual requirement of the individual and society, fostering posterity’s spiritual growth and civilization, said Swami Nirviseshananda Tirtha in a discourse.
The subject matter of the Upanishads is human experience, and hence the validity of their study and observations can be established at the experiential rather than the rational level. For instance, the Upanishad seers, while observing the various phenomena in the external world, such as day and night or the seasons following one another, the birth, growth, decay and death of all living beings, etc, as characterised by constant change, also recognised the presence of something eternal behind all this ceaseless activity. Another important discovery is that in all beings there is the basic desire to remain happy. They have identified this yearning to be the result of an inherent lack or insufficiency or emotional gap. Ironically, when people in search of happiness are driven to look for it in the world around, this effort is sure to remain ever elusive. For, one may go on interacting with the world hoping he will somehow gain that happiness, only to be disappointed. Even if one possesses the whole world there is no guarantee that it will be his always. Moreover, fresh desires will arise. The seers have shown thus that the essence of happiness is within each one in the undying immortal self that has to be recognised.