There have been two parallel tracks of inquiry and discovery in the history of humankind.
The first is that of what we perceive to be the external world: the world of space and time; the world, literally, of our environment and humble beginnings. Such explorations have been undertaken by both explorers and scientists who have defied conventional wisdom and who continually seek to expand knowledge. I will leave the history of such explorations and the naming of those explorers to the history and science books. However, today, with our telescopes and microscopes, with our spaceships and space probes, with our laboratories and computer simulations, we have learned so much about our biological DNA, the earth and all its life, and the universe in fields that include molecular biology and genetics to astrophysics and astrobiology to cosmology and quantum physics. In just a few short millennia, humankind has moved from living in caves or on the savannah to sending space probes beyond the boundaries of our solar system. However, no one would disagree that there is likely so much more to learn and to discover.
The second track of exploration and discovery is that of our own consciousness. The type of exploration has its own long history and has roots in all the mystical traditions of the world’s religions and various cultures. This exploration has been less visible, less acknowledged, and less influential, at least on a mass scale. And contrary to the first track, what continually is discovered is the same, whether that ‘discovery’ occurred 2500 or 2000 years ago or today.
It is the exploration of our own consciousness that, to me, is the final and perhaps only frontier of human inquiry, with the irony that there is nothing to explore and nothing to find. Such exploration is not grand nor grandiose by any means. It will never make the front page of our newspapers or headlines of our internet media: “Masses of people wake up to their true nature!” Such exploration is a private matter; unobtrusive and unobserved by others, except perhaps those who also engage in such exploration and discuss it among themselves.