Many persons imagine that, if they returned to a primitive diet of this character, they would become as the savages—wild and uncivilised. They “don’t want to become like the animals,” they will say. They wish to remain “civilised,” and not return to a state of savagery and barbarism! There is no logic in this argument—indeed, no sense. Because a man lives upon fruits and nuts, it is, of course, no reason why he should return to a primitive state, mentally; indeed, there is far less evidence for this than there is that man becomes like the carnivorous animals by eating meat. There is evidence for that! But living upon fruits and nuts has no other effect than to elevate the tone and character of the body; to increase its energies and to render the mind clearer and more active. If these objectors to the fruitarian diet would only study physiology and human nature before passing any such absurd judgment upon the facts, their arguments would have more force—but then, in that case, they would not raise the arguments at all! Of course, this whole idea is conclusively proved to be erroneous by the facts in the case.
There is one other point I should like to touch upon, though briefly, before passing on to the main argument of the book. The usual position with regard to food, and its functions in the body is this. Food has three functions: (1) The replacement of tissues which have been broken down as the result of the day’s work; (2) the maintenance of the bodily energy; and (3) the maintenance of the bodily heat. Now, in my former book,[1] I advanced a number of facts tending to show that food has but one function—replacing broken-down tissue. It supplies no heat and no energy whatever to the body, at any time, or under any circumstances. Both the heat and the energy are due to another source altogether, and not to the food ingested.[2] I cannot enumerate the arguments in support of this position here; they will be found in full in the work referred to; but I would point out that, if this theory were true, it would cause us to modify very largely the views entertained as to the necessary amount of food required by the body. Now, a large percentage of the food eaten is supposed to create heat and energy, or at least liberate it, and is eaten for that express purpose. But if it be true that food has no other function than to supply the body with material for the rebuilding of its structures and tissues, it will be apparent that far less food is necessary than is usually thought to be necessary by the physiologists; and this would account for the enormous differences in quantity said to be
necessary by the various physiologists. The truth of the matter doubtless is, that the smallest amount of food is that which is necessary, and all amounts over and above this are passed through the body at an expense of the vital energies, and to the detriment of the vital economy. However, I shall not dwell unduly upon this point, in this place; partly because Dr Rabagliati and myself are, as yet, practically alone in our belief that the energy of the body does not come from the food; and partly because this book is devoted to the quality of the various foods, rather than to their quantity—as was my former book. Both—quantity and quality—are of great interest and importance; but as I have already said all that is necessary regarding one aspect of this question—that of quantity—I feel that a somewhat detailed discussion of the “quality” of food could not fail to be of interest. I accordingly turn to this aspect of the problem; and shall devote the remaining pages of this book to a discussion of the relative qualities and proportions of the various foods.
II
THE ARGUMENT FROM COMPARATIVE ANATOMY
Perhaps the most important factor of all, in considering this question of man’s natural diet, is the anatomical argument—the argument, that is, which says that man must or should naturally eat certain foods, for the reason that he belongs to the class or genus of animals which lives upon that class of foods—and that, consequently, he should live upon them also. Comparative anatomy affords us one of the most tangible and at the same time one of the most forceful and convincing arguments that can be furnished in favour of man’s natural diet (whatever that may prove to be)—for the reason that its facts are so well-attested that they cannot be gainsaid by anyone who is in possession of them; and only the inferences drawn from these facts can be disputed—which is a question that will be considered later. As before stated, this line of argument is in many ways the most important with which we shall have to deal; it will tend either to condemn or to confirm my argument most strongly. From a scientific standpoint, the study of this subject is founded upon the fact that the diet of any animal, in its natural state, is always found to agree both with its anatomical structure and with its several digestive processes and general bodily functions. So clearly is this fact recognised, indeed, by comparative anatomists and scientists generally, that animals have been divided, according to their dietetic habits, into four great classes—herbivorous, frugivorous, carnivorous and omnivorous. There are various sub-and minor-divisions that can be and in fact are made—such as the gramnivora, or grain-eaters; the rodentia, or gnawers; the ruminants, or cud-chewers; and the edentata or creatures without teeth. These subdivisions need not concern us here, however; and I shall not discuss their anatomical structure or food-habits at any length. Their names sufficiently classify them—in a work of this nature, which deals with foods, and is not a natural history. For practical purposes, the gramnivora may be included in the class of frugivora—since most frugivorous animals eat grains to some extent. This understood, we can proceed to a consideration of the facts; and we shall see to which of these classes man belongs.
In order to classify an animal, and place him in his proper division, it is necessary first of all to make a careful examination of his physical structure, and examine his organs in turn and severally, with the utmost care; when, by a comparative study of his organs, and by comparing them with those of other animals, living upon other foods, we shall be enabled to classify man properly—at least, so far as the evidence afforded by comparative anatomy enables us to reach a decisive conclusion one way or the other. There are numerous other facts and arguments to be taken into consideration; but, as said before, the argument drawn from comparative anatomy is the most complete and convincing of all—since that alone practically settles the case for all other animals. Let us, therefore, consider the structure or anatomy of man, from this point of view; and see how far these arguments lead us, and to what class we should naturally assign man, from a study of these facts alone. I shall take up for discussion first of all the teeth.