The "unknown world" that Jacob Needleman refers to is the inner world, the subjective world of direct and immediate experience, the world of consciousness and creativity and, yes, spiritual illumination. The outer world, on the other hand, is the world that we can touch and taste and measure with our five senses, the physical world of mass and energy and location. These inner and outer worlds are inextricable from, interpenetrated with, and irreducible to one another. And though the inner world has been carefully charted and explored by some of history's greatest philosophers, sages, and scientists, only the outer world of extreme scientific materialism finds any real mainstream credibility. The inner world yet has been abandoned by today's intellectuals, and largely forgotten by the masses. The universe has been gutted of its interiors—exteriors alone are considered "real", leaving us to scrape for meaning in the empty, hollow shell of reality.
But we are born of this world, we are indivisible from this world, and if we want to truly understand the world and our place in it, we must embrace and enact the totality of our knowledge, wisdom, and insight, inside and out. We can no longer allow the inner world to remain unknown. As Jacob says, "If the world is alive, it is either growing or dying," and because humanity is evolution's latest and greatest experiment on this planet, we are the ones to decide which way it goes.
The evolution of our planet depends upon the evolution of our species. We are have created enormously complex challenges for ourselves and for our world, challenges that require an entirely new level of intuition and problem solving. Now more than ever we need to recover the timeless wisdom and effortless compassion of the inner world; to integrate our hearts with our minds and our souls with our senses. We are called to seek a new synthesis of knowledge and wisdom for the 21st century, an embodied understanding of ourselves and our world, an empirical mysticism to supplement an empirical science—a discovery that could itself represent one of the greatest evolutionary steps our planet has taken since we stood up on two legs.