The Kena Upanishad in a striking and challenging way throws light on the knowledge of spiritual truth. Study and reflection on it can help us in our search for inner illumination.

How can it help us? In the non-dual tradition, the Upanishads and comparable texts have a particular purpose. Put simply, it is to tell us things that we cannot find out from any other source. Three main ways of gaining knowledge are recognized. They are the senses, reason (inference and so on), and spiritual texts (what might be called 'Scripture' or 'the Vedas', but we do not want to imply that Truth is exclusive to any one particular religion).

Our senses tell us about the world. If we need to know facts about the world around us, it is the senses that should be consulted; they are the competent authority here. Reason tells us the relations and implications between facts. Sense data and reason together are the way we gain knowledge of the empirical world. Science uses these tools in a very disciplined and precise way, which is why it is so effective in understanding the physical world around us.

But there are some things that the senses and mind cannot tell us about. Their competence fails as regards what lies beyond the mind and senses. The mind and senses are part of the world, they are details within the whole, so evidently they are not able to know the whole of reality over and above the very limited range of experience that is available to the mind and senses.

According to the traditional teachings, this is precisely the place where texts such as the Upanishads are the right authority. They are the recorded utterances of those who have realized the one Self at the heart of all in direct experience, the reality behind and beyond the mind and senses. There the senses and mind do not operate; it is not knowledge by knowing but knowledge by being.