The purest lesson our era has taught is that man, at his highest, is an individual, single, isolate, alone, in direct soul-communication with the unknown God, which prompts within him. This lesson, however, puts us in danger of conceit, especially spiritual conceit. In his supreme being, man is alone, isolate, nakedly himself, in contact only with the unknown God. This is our way of expressing Nirvana. But just as a tree is only perfect in blossom because it has groping roots, so is man only perfected in his individual being by his groping, pulsing unison with mankind. The unknown God is within, at the quick. But this quick must send down roots into the great flesh of mankind. In short, the “spirit” has got a lesson to learn: the lesson of its own limitation. This is for the individual. And the infinite, which is Man writ large, or Humanity, has a still bitterer lesson to learn. It is the individual alone who can save humanity alive. But the greatest of great individuals must have deep, throbbing roots down in the dark red soil of the living flesh of humanity. Which is the bitter pill which Buddhists and all advocates of pure _Spirit_ must swallow. In short, man, even the greatest man, does not live only by his spirit and his pure contact with the Godhead--for example, Nirvana. Blessed are the pure in heart, Blessed are the poor in spirit. He is _forced_ to live in vivid rapport with the mass of men. If he denies this, he cuts his roots. He intermingles as the roots of a tree interpenetrate the fat, rock-ribbed earth. How? In this same vertebral correspondence. The mystic may stare at his own navel and try to abstract himself for ever towards Nirvana: it is half at least illusion. There is all the time a powerful, unconscious interplay going on between the vertebral centres of consciousness in all men, a deep, mindless current flashing and quivering through the family, the community, the nation, the continent, and even the world. No man can _really_ isolate himself. And this vertebral interplay is the root of our living: must always be so. And this vertebral interplay is subject to the laws of polarity, since it is an intercommunion of active, polarised conscience-force. There is a dual polarity, and a dual direction. There is the outward, or downward pulse, in the great motion of sympathy or love, the love that goes out to the weaker, to the poor, to the humble. The vast, prostrate mass now becomes the positive pole of attraction: woman, the working-classes. The whole of the great current of vertebral consciousness in mankind is supposed, now, to run in this direction. But the whole movement is but a polarised circuit. Insist on one direction overmuch, derange the circuit, and you have a terrible débâcle. Which brings us to another aspect of relativity: relativity in dynamic living.