And how shall you purify the physical body? You must regulate it in all its activities—in sleep, in food, in exercise, in everything. You cannot have a pure physical body with impure mental and astral bodies so that the work of imagination helps also in the purification of the physical. But you must also regulate the physical body in all its activities. Take for instance, food. The Indian says truly that every sort of food has a dominant quality in it, either rhythm, or activity, or inertia, and that all foods fall under one of these heads. Now the man who is to be a yogi must not touch any food which is on the way to decay. Those things belong to the tamasic foods—all foods, for instance, of the nature of game, of venison, all food which is showing signs of decay (all alcohol is a product of decay), are to be avoided. Flesh foods come under the quality of activity. All flesh foods are really stimulants. All forms in the animal kingdom are built up to express animal desires and animal activities. The yogi cannot afford to use these in a body meant for the higher processes of thought. Vitality, yes, they will give that; strength, which does not last, they will give that; a sudden spurs of energy, yes, meat will give that; but those are not the things which the yogi wants; so he puts aside all those foods as not available for the work he desires, and chooses his food out of the most highly vitalised products. All the foods which tend to growth, those are the most highly vitalised, grain, out of which the new plant will grow, is packed full of the most nutritious substances; fruits; all those things which have growth as their next stage in the life cycle, those are the rhythmic foods, full of life, and building up a body sensitive and strong at the same time. Dwellers on the Threshold