Of these there are many kinds. First, elementals. They try to bar the astral plane against man. And naturally so, because they are concerned with the building up of the lower kingdoms, these elementals of form, the Rupa Devas; and to them man is a really hateful creature, because of his destructive properties. That is why they dislike him so much. He spoils their work wherever he goes, tramples down vegetable things, and kills animals, so that the whole of that great kingdom of nature hates the name of man. They band themselves together to stop the one who is just taking his first conscious steps on the astral plane, and try to frighten him, for they fear that he is bringing destructiveness into the new world. They cannot do anything, if you do not mind them. When that rush of elemental force comes against the man entering on the astral plane, he must remain quiet, indifferent, taking up the position: “I am a higher product of evolution than you are; you can do nothing to me. I am your friend, not your enemy, Peace!” If he be strong enough to take up that position, the great wave of elemental force will roll aside and let him through. The seemingly causeless fears which some feel at night are largely due to this hostility. You are, at night, more sensitive to the astral plane than during the day, and the dislike of the beings on the plane for man is felt more strongly. But when the elementals find you are not destructive, not an embodiment of ruin, they become as friendly to you as they were before hostile. That is the first form of the dweller on the threshold. Here again the importance of pure and rhythmic food comes in; because if you use meat and alcohol, you attract the lower elementals of the plane, those that take pleasure in the scent of blood and spirits, and they will inevitably prevent your seeing and understanding things clearly. They will surge round you, impress their thoughts upon you, force their impressions on your astral body, so that you may have a kind of shell of objectionable hangers-on to your aura, who will much obstruct you in your efforts to see and hear correctly. That is the chief reason why every one who is teaching Yoga on the right-hand path absolutely forbids indulgence in meat and alcohol.