An excitant applied to an organ or part occasions exaltation of its functional activities and an elevation of its sensations. If the irritating effect is prolonged or intensified there follows sensations of uneasiness, which increase to tenderness, and then to decided pain, or, if the irritation is great enough, stupor results. Irritated parts become exhausted and incapable of vigorous physiological action.

Pain is simply sensation or feeling so intensified as to be uncomfortable. It is the nervous system noting the presence of danger, giving warning of the damages being done to the part, and arousing the vital energies to vigorous resistance to pathogen. Pain does not merely warn us against intrinsically damaging things and influences, but also against damaging excesses of wholesome things and influences. Pain is excess feeling and serves a very useful protective function.

Things that give pleasure may be carried far enough that the pleasurable sensation passes into pain. Pain is an exaltation of the sense of feeling and depends on the capacity to feel and enjoy.

It is literally true that the capacity of an organism for enjoyment may be measured by its capacity to suffer. The more elevated is an animal in the scale of life--the more highly organized its nervous system--the greater are its capacities for pleasure and pain.

Suffering, that is the capacity to suffer, is absolutely necessary for our protection and preservation and, to this extent, in both the moral and utilitarian sense, pain is good and not evil. Enjoyment comes from obedience to the laws of being and suffering from violating these laws. Fixed laws of life are essential. They injure only when violated, and the consequent suffering acts as a school master to compel man to behave himself. It is the warning voice of Nature telling us that something is wrong or that the thing we are doing is harmful.

Suffering is an incentive to man to adjust himself to the laws of life, to adapt himself to his natural environment, or to adapt his unnatural environment to his needs. Without hunger to drive an animal to eat he would starve; without thirst he would perish in the presence of water; without pain from cold he would freeze without ever knowing the cause; without suffering from heat he would be consumed by fire; without pain from pressure his body would be crushed without warning. Pain from "disease" and injury is an evidence of a need for a rest and a change of life. Gratification of desire becomes painful when carried to excess, and pain in such cases is necessary to prevent complete exhaustion and death. If man were capable of pleasure only and not of pain he would speedily exhaust the powers of life. Pain is a very effectual check to conduct which would otherwise lead to destruction. The office of pain is not to destroy us, but to save us. It is man's best friend.

All of man's powers are intended for good and serve good purposes when used in harmony with their primitive constitution. Man can govern his powers and use them rightly or wrongly. If he uses them wrongly, pain and suffering call a halt. Pain is Nature's "thou shalt not."

Man's appetites and passions stand on a lower plane than Ms higher mental faculties. When these passions and appetites are governed by will and reason in harmony with their primitive purposes and are not permitted to become masters over the higher powers, they serve noble ends. But when they become masters and the higher powers are made slaves to them, human nature is debased. From this, it will be seen that man should control and direct his appetites and passions aright and not attempt to eradicate them as certain Eastern religions demand. Their proper exercise brings pleasure. Their wrongful exercise brings pain, and the pain is commensurate with the pleasure their right exercise affords. Pain is life's guardian angel.

The gratification of desire becomes painful if pushed to excess. All pleasures become painful if pushed beyond the limits of safety. The intensest pleasures are the costliest and occasion the most pain if overindulged. This is the reason that relief of pain is an evil. It checks Nature's check. It enables us to go on heedless of the price we are paying. It is one thing to silence the outcry of nature with pain killers, but quite another to correct and remove the conditions that give rise to it.

Pain is not merely a warning to the one who suffers; it is part of the means employed to rally and mobilize reserve vital energies to the point of the pain to resist the encroachment of Pathogen. It may well be true that pain is essential to the increased flow of blood to the site of injuries and that it is of great importance from a remedial point of view. Pain stimulates the adrenal glands causing more adrenalin to be thrown into the blood and increases the coagulating power of the blood. There are doubtless other beneficial blood changes resulting from its influence. Pain is an index to vitality.

Pain is dull, heavy, acute, mild, severe, lacerating, darting, or stellate, according to its degree, or mode of manifestation; but in all cases it is an evidence of wrong and not itself the wrong. It is not the evil; only the protest against an evil. The exhaustion and feebleness sequent to intense pain and prolonged irritation form no evidence that pain and irritation constitute evil.

If we pinch our arm pain is felt. The nerves recognize and warn us of the injury being inflicted. It does not require much knowledge of vital phenomena to determine whether the pain that warns us, or the pinching that harms us, constitutes the real mischief. If a man is cut by a sharp knife he feels great pain. Is the pain in such a case to be regarded as "disease" and suppressed, or is it the living, vital witness to the outrage done to the body by the knife. Pour undiluted sulphuric acid upon the skin. The structures are chemically corroded and the parts immediately under the ones thus destroyed are extremely sensitive, highly irritated, and painful. Is the pain and (irritation) the "disease", or are these the means of notifying the victim of the damage done?

In neither of these cases does the danger consist in the recognition by the nervous system of the presence of the damage and the damaging agent, which recognition we call pain, but in the outrage done to the living tissues by these agents. The real danger is the pinch, or cut, or corrosion.

While the capacity to suffer pain, to be irritated and aroused into a vigorous "fever", must ever exist in the healthy body and are all part of the means of preserving life, let no one suppose that because pain and irritation are not themselves evil, they should be present in a state of health. Nor, should it be supposed that when pain is smothered by some form of anodyne the trouble, of which it is a symptom, has been remedied.

However undesirable pain may be, in itself, its suppression is not desirable. Its existence is an evidence of injury and the increase of sensibility may be, and I believe is, a direct means of "exciting" an increase of vital action in the part. If the power to suffer is taken from the damaged nerves, nothing whatever is done toward removing the antecedents of the pain and the repair of damages; but Nature's outcry and rally are forestalled.