God made the senses turn outwards, man therefore looks outwards, not into himself. Now and again a daring soul, desiring immortality, has looked back and found himself. He who knows the soundless, odourless, tasteless, intangible, formless, deathless, supernatural, undecaying , beginingless, endless, unchangeable Reality, spring out of the mouth of Death.
~ Katha Upanishad.