It will be observed that in my endeavour to reply to the simple question of "What must I eat?" I have adhered closely to the conventional system of mixed feeding practised in this and most civilised countries. This must not be taken as an indication that I have no sympathy with those who for one reason or another consider it advisable to restrict themselves to some other system. On the contrary, I am satisfied that it is not only perfectly possible to live on a system which includes no flesh food whatsoever, but that many people will find it advantageous so to do.

But a simple question demands a simple answer, although the resources of our language are so infinite that simplicity in rejoinder is the exception and not the rule. Nor could it be very well otherwise unless the conditions were specifically defined, for there are at present more than a dozen systems of diet before the public, each one claiming to be the only infallible way to perfect health. Yet no two are in perfect agreement, and most of them are hopelessly at variance with one another.

The vegetarian demands that nothing be eaten but products of the vegetable kingdom, although he recognises with some degree of reluctance that the ovo-lacto-vegetarians must be admitted into the fold, while the latter sect is broad-minded enough to view with favour the man who adds the flesh of fish - a coldblooded animal - to his menu.

The low-protein advocate has no special predilections on the question of quality, but rigidly restricts the quantity of his proteins, whether animal or vegetable, i.e. fish, flesh, fowl, milk, eggs, cheese, peas, beans, or lentils, and does not despise a good cigar or even a glass of wine.

The uric-acid-free dietist, on the other hand, views with horror fish, flesh, fowl, peas, beans, and lentils, tea, coffee, cocoa, meat-soups, beef-teas, and gravies, and regards with grave suspicion sundry other foods supposed to contain uric acid, e.g. oatmeal and wholemeal bread, asparagus, and mushrooms, on the plea that all those substances because of their content of uric acid are rank poisons to the body. Yet he eats very considerable quantities of starchy and fatty foods, which are largely proscribed by the individual who favours the doctrine of hyper-pyraemia which suggests that most diseases are the outcome of even a very small modicum of these energy-producing foods.

Milk might easily be held to be above suspicion as the primary and elemental food of all mankind and many of the lower animals, but the amount of lime it contains is considered dangerous by a small sect which, for somewhat similar reasons, is closely allied to the salt-free cranks. This last sect not only never adds salt to its food, but even places its ban upon perfectly wholesome foods containing a little common salt, and thus places itself in opposition to those who use sea water as a cure for most of the ills that flesh is heir to. The mention of water directs our attention to those who never drink a drop of fluid at any of their meals, and little, if any, at other times.

Yeast is looked upon with abhorrence by many who do not otherwise object to cooked food, whilst the "raw-fooders" profess to eat food in an unfired condition, although they do not despise the thermal rays emanating from electricity as a means of making this food more attractive. The curdled-milk cult has all but died a natural death, although "chewers" are still to the fore, but the no-breakfast plan has recently retired in favour of the fasting fad, which only requires steady perseverance to exterminate all who disagree with any of the methods already mentioned.

Is it any wonder that the plain man, the man who asks a straight question and expects a straight answer, should be left stranded on the verge of despair? He is hardly in better case than the would-be religious devotee in search of the correct sect amongst the more than two hundred religious bodies in this country. And yet he does not cease to eat any more than the wise man ceases to worship, although he, at any rate, has solved his problem by recognising the common ground which is sacred to all the religious sects, that "actions speak louder than words."

Is it possible to find an underlying principle of action which might be applied in the case of diet of such universal application that no simple member of any of the sects can with any degree of assurance find it in his heart to object to it? The reply to this question is of course conditional on the querist being a fairly healthy individual, and not suffering from any gross form of disease, as, for instance, diabetes, which requires a special form of dieting. The answer to the question, therefore, is that the healthy man can live on any system of diet by attention to moderation and regularity, but the unhealthy man must look to the dietetic expert - not the dietetic faddist - to guide him in the selection of the best system or kind of foods to suit his individual case. All old men attribute their longevity to great moderation in diet, and especially to a minimum allowance of flesh food, the great stimulating properties of which are not sufficiently recognised.

The one thing upon which all these sects agree is the diminished amount of food, and so the only conception which appears to unite them is the fundamental doctrine of moderation, which has not only been taught from time immemorial, but is actually practised by all sensible men at the present time. In this connection Abernethy's famous prescription to "live on sixpence a day and earn it" - by muscular exercise, I presume - may be recalled. His original advice to a wealthy patient suffering from indigestion was to steal a horse, so that the incarceration which would be the outcome of this exploit would compel a parsimonious regimen and diet. Cyrus, the creator of the Persian Empire, subsisted from early childhood on the simplest and plainest diet of vegetable food and water, whilst his soldiers adhered to the same rigorous fare. Edison tells us that for two months he lived on 12 ounces of food per day, taking absolutely no exercise and retaining his weight of 185 lbs. Sidney Smith, who in the evening of his days confessed to suffering from "seven distinct diseases," was a victim of overeating, and declared that he "never saw any gentleman who ate and drank as little as was reasonable."

One must therefore select the system which pleases and suits him best, practise it with the greatest moderation, and he need have no qualms of conscience that the nutrition of his body will suffer in any serious degree.