A curious and not altogether comforting reflection is that if the inexpensive and simple food of the agricultural labourer is sufficient, the section of the community which spends from five to ten shillings per head a day on a mixed diet of meat, fish, eggs, and vegetables is guilty of waste and excess. Here, however, the remarkable, and, in fact, exceptional domination of "habit" (in the case of man), in regard to both the actual articles of food and the mode of its preparation, has to be recognised. Such and such inexpensive and unskilfully prepared food may contain more than the necessary amount of proteids (that is, matters like flesh, the casein of cheese and of vegetables, and the albumen of eggs), of hydro-carbons (_i.e._, fats), of carbo-hydrates (_i.e._, starch and sugar), yet if you were suddenly to compel a man accustomed to well-cooked meat to live on such food he would be unable to assimilate it, his digestive organs would refuse to work, and he would become, if not seriously ill, yet so ill-nourished and sickly that he would be unfit for his work and readily fall a victim to disease. It is, in fact, impossible to lay down any scheme of diet based on the mere provision of the necessary quantities of food materials whilst ignoring the formed habits of the individual and the relation of the psychical conditions which we call "taste," "appetite," "fancy," "disgust," to the actual processes of digestion and the consequent efficiency of the proposed diet. No doubt gradually, after a few generations, a whole people may become healthily habituated to a diet which would have been positively injurious to their forebears, and no doubt individuals may be led by fortitude or by necessity in time (perhaps weeks, perhaps years) to acquire a tolerance, or even enjoyment, of food at first repulsive, and therefore injurious. The difficulty in the matter is not that of correctly determining what is physiologically sufficient for the human animal, nor even what would be a healthy diet for a community when once, after a transition period of distress and injury, habituated or "attuned" to that diet. The difficulty is to arrive at a conclusion as to what is really the suitable and reasonable diet for an individual--yourself or one like yourself--having regard to the lifelong habits of the individual, and the consequent nervous reactions established in him or her in relation to the taste, quality, and mode of presentation of food. Robust people, so long as they get what suits their own uncultivated taste, are apt to make very light of what they call "fancies" about food, and to overlook their real importance.