Sri Aurobindo
Letters of Sri Aurobindo
Volume I - Part 2
Each man has his own personal consciousness entrenched in his body and gets into touch with his surroundings only through his body and senses and the mind using the senses.
Yet all the time the universal forces are pouring into him without his knowing it. He is aware only of thoughts, feelings etc. that rise to the surface and these he takes for his own. Really they come from outside in mind waves, vital waves, waves of feeling and sensation etc. which take particular forms in him and rise to the surface after they have got inside.
But they do not get into his body at once. He carries 
about with him an environmental consciousness (called by the Theosophists the aura) into which they first enter. If you can become conscious of this environmental self of yours, then you can catch the thought, passion, suggestion or force of illness, or whatever it may be, before it enters and prevent it from entering into you. If things in you are thrown out, they often do not go altogether but take refuge in this environmental atmosphere and from there try to get in again or they go to a distance outside but linger on the outskirts or even perhaps far off, waiting till they get an opportunity to attempt entrance.