“Everything is done with a view to cure the disease, without any regard to its cause, and the disease is considered as the infliction of some supernatural being. Therefore, in the progress of the healing art thus far, not a step is taken towards investigating the laws of health and the philosophy of disease.

“Nor, after Medicine had received a more systematic form, did it apply to those researches which were most essential to its success, but, like religion, it became blended with superstitions and absurdities. Hence, the history of Medicine, with very limited exceptions, is a tissue of ignorance and error, and only serves to demonstrate the absence of that knowledge upon which alone an enlightened system of Medicine can be founded, and to show to what extent a noble art can be perverted from its capabilities of good to almost unmixed evil by the ignorance, superstition, and cupidity of men. In modern times, anatomy and surgery have been carried nearly to perfection, and great advance has been made in physiology. The science of human life has been studied with interest and success, but this has been confined to the few, while even in our day, and in the medical profession itself, the general tendency is adverse to the diffusion of scientific knowledge.

“The result is, that men prodigally waste the resources as if the energies of life were inexhaustible; and when they have brought on disease which destroys their comforts, they fly to the physician, not to learn by what violation of the laws of life they have drawn the evil upon themselves, and by what means they can avoid the same; but, considering themselves visited with afflictions which they have in no manner been concerned in causing, they require the physician’s remedies, by which their sufferings may be alleviated. In doing this, the more the practice of the physician conforms to the appetites of the patient, the greater is his popularity and the more generously is he rewarded.

“Everything, therefore, in society tends to confine the practising physician to the department of therapeutics, and make him a mere curer of disease; and the consequence is, that the medical fraternity have little inducement to apply themselves to the study of the science of life, while almost everything, by which men can be corrupted, is presented to induce them to become the mere panderers of human ignorance and folly; and, if they do not sink into the merest empiricism, it is owing to their own moral sensibility rather than to the encouragement they receive to pursue an elevated scientific professional career.

“Thus the natural and acquired habits of man concur to divert his attention from the study of human life, and hence he is left to feel his way to, or gather from what he calls experience, all the conclusions which he embraces. It has been observed that men, in their (so-called) inductive reasonings deceive themselves continually, and think that they are reasoning from facts and experience, when they are only reasoning from a mixture of truth and falsehood. The only end answered by facts so incorrectly apprehended is that of making error more incorrigible. Nothing, indeed, is so hostile to the interests of Truth as facts incorrectly observed. On no subjects are men so liable to misapprehend facts, and mistake the relation between cause and effect, as on that of human life, health, and disease.”

“We have been told that some enjoy health in warm, and others in cold climates some on one kind of diet, and under one set of circumstances, and some under another; that, therefore, what is best for one is not for another; that what agrees well with one disagrees with another; that what is one man’s meat is another man’s poison; that different constitutions require different treatment; and that, consequently, no rules can be laid down adapted to all circumstances which can be made a basis of regimen to all.

“Without taking pains to examine circumstances, people consider the bare fact that some intemperate individuals reach old age evidence that such habits are not unfavourable to life. With the same loose reasoning, people arrive at conclusions equally erroneous in regard to nations. If a tribe, subsisting on vegetable food, is weak, sluggish, and destitute of courage and enterprise, it is concluded that vegetable food is the cause. Yet examination might have shown that causes fully adequate to these effects existed, which not only exonerated the diet, but made it appear that the vegetable diet had a redeeming effect, and was the means by which the nation was saved from a worse condition.

“The fact that individuals have attained a great age in certain habits of living is no evidence that those habits are favourable to longevity. The only use which we can make of cases of extraordinary old age, is to show how the human constitution is capable of sustaining the vital economy, and resisting the causes which induce death.

“If we ask how we must live to secure the best health and longest life, the answer must be drawn from physiological knowledge; but if we ask how long the best mode of living will preserve life, the reply is, Physiology cannot teach you that. Probably each aged individual has a mixture of good and bad habits, and has lived in a mixture of favourable and unfavourable circumstances. Notwithstanding apparent diversity, there is a pretty equal amount of what is salutary in the habits and circumstances of each. Some have been ‘correct’ in one thing, some in another. All that is proved by instances of longevity in connexion with bad habits is, that such individuals are able to resist causes that have, in the same time, sent thousands of their fellow-beings to an untimely grave; and, under a proper regimen, they would have sustained life, perhaps, a hundred and fifty years.

“Some have more constitutional [or inherited] powers to resist the causes of disease than others, and, therefore, what will destroy the life of one may be borne by another a long time without any manifestations of immediate injury. There are, also, constitutional peculiarities, but these are far more rare than is generally supposed. Indeed, such may, in almost every case, be overcome by a correct regimen. So far as the general laws of life and the application of general principles of regimen are considered, the human constitution is one: there are no constitutional differences which will not yield to a correct regimen, and thus improve the individual. Consequently, what is best for one is best for all.... Some are born without any tendency to disease while others have the predisposition to particular diseases of some kind. But differences result from causes which man has the power to control, and it is certain that all can be removed by conformity to the laws of life for generations, and that the human species can be brought to as great uniformity, as to health and life, as the lower animals.”

“Physiological science affords no evidence that the human constitution is not capable of gradually returning to the primitive longevity of the species. The highest interests of our nature require that youthfulness should be prolonged. And it is as capable of being preserved as life itself, both depending on the same conditions. If there ever was a state of the human constitution which enabled it to sustain life [much beyond the present period], that state involved a harmony of relative conditions. The vital processes were less rapid and more complete than at present, development was slower, organisation more perfect, childhood protracted, and the change from youth to manhood took place at a greater remove from birth. Hence, if we now aim at long life, we can secure our object only by conformity to those laws by which youthfulness is prolonged.”

The ourang-outang, on being domesticated, readily learns to eat animal food. But if this proves that animal to be omnivorous, then the Horse, Cow, Sheep, and others are all omnivorous, for everyone of them is easily trained to eat animal food. Horses have frequently been trained to eat animal food,[267] and Sheep have been so accustomed to it as to refuse grass. All carnivorous animals can be trained to a vegetable diet, and brought to subsist upon it, with less inconvenience and deterioration than herbivorous or frugivorous animals can be brought to live on animal food. Comparative anatomy, therefore, proves that Man is naturally a frugivorous animal, formed to subsist upon fruits, seeds, and farinaceous vegetables.[268]

“Yet by so much as the stimulation exceeds that which is necessary for the performance of the functions of the organs, the more does the expenditure of vital powers exceed the renovating economy; and the exhaustion which succeeds is commensurate with the excess. Hence, though food which contains the greatest proportion of stimulating power causes a feeling of the greatest strength, it also produces the greatest exhaustion, which is commensurately importunate for relief; and, as the same food affords such by supplying the requisite stimulation, their feelings lead the consumers to believe that it is most strengthening.... Those substances, the stimulating power of which is barely sufficient to excite the digestive organs in the appropriation of nourishment, are most conducive to vital welfare, causing all the processes to be most perfectly performed, without any unnecessary expenditure, thus contributing to health and longevity.

“Flesh-meats average about thirty-five per cent of nutritious matter, while rice, wheat, and several kinds of pulse (such as lentils, peas, and beans), afford from eighty to ninety-five per cent; potatoes afford twenty-five per cent of nutritious matter. So that one pound of rice contains more nutritious matter than two pounds and a half of flesh meat; three pounds of whole meal bread contain more than six pounds of flesh, and three pounds of potatoes more than two pounds of flesh.”

“The peasantry of Norway, Sweden, Denmark, Germany, Turkey, Greece, Italy, Switzerland, France, Spain, England, Scotland, Ireland, a considerable portion of Prussia, and other parts of Europe subsist mainly on non-flesh foods. The peasantry of modern Greece [like those of the days of Perikles] subsist on coarse brown bread and fruits. The peasantry in many parts of Russia live on very coarse bread, with garlic and other vegetables, and, like the same class in Greece, Italy, &c., they are obliged to be extremely frugal even in this kind of food. Yet they are [for the most part] healthy, vigorous, and active. Many of the inhabitants of Germany live mainly on rye and barley, in the form of coarse bread. The potato is the principal food of the Irish peasantry, and few portions of the human family are more healthy, athletic, and active, when uncorrupted by intoxicating substances [and, it may be added, when under favourable political and social conditions]. But alcohol, opium, &c. [equally with bad laws] have extended their blighting influence over the greater portion of the world, and nowhere do these scourges so cruelly afflict the self-devoted race as in the cottages of the poor, and when, by these evils and neglect of sanitation, &c., diseases are generated, sometimes epidemics, we are told that these things arise from their poor, meagre, low, vegetable diet. Wherever the various sorts of intoxicating substances are absent, and a decent degree of cleanliness is observed, the vegetable diet is not thus calumniated.

“Taking all flesh-eating nations together, though some, whose other habits are favourable, are, comparatively, well-formed, as a general average they are small, ill-formed races; and taking all vegetable-eating nations, though many, from excessive use of narcotics, and from other unfavourable circumstances, are comparatively small and ill-formed, as a general average they are much better formed races than the flesh-eaters.[269] It is only among those tribes whose habits are temperate, and who subsist on the non-flesh diet, that the more perfect specimens of symmetry are found.

“Not one human being in many thousands dies a natural death. If a man be shot or poisoned we say he dies a violent death, but if he is ill, attended by physicians, and dies, we say he dies a ‘natural’ death. This is an abuse of language—the death in the latter case being as truly violent as if he had been shot. Whether a man takes arsenic and kills himself, or by small doses or other means, however common, gradually destroys life, he equally dies a violent death. He only dies a natural death who so obeys the laws of his nature as by neither irritation nor intensity to waste his energies, but slowly passes through the changes of his system to old age, and falls asleep in the exhaustion of vitality.”[269]