About the causes of pain in general

Since pain is one of the unnatural sensations that takes place in the body of an animal, let’s talk about its causes, generally speaking, and say: pain is a feeling of something unpleasant. The totality of causes of pain are reduced into two categories: this is the category of causes that suddenly change nature, that is, causing a disorder of a dissimilar nature, and the category of causes that violate continuity. By a disorder of dissimilar nature I mean when in the substance of an organ of a certain nature a foreign nature arises, opposite to the original one, so that the organs become hotter or colder than before. The sentient force senses the appearance of something unpleasant, and the organ experiences pain. Pain, therefore, is expressed in the fact that the unpleasant factor is felt as something unpleasant.

As for the disorder of the consonant nature, it does not cause pain at all and you cannot feel it. This happens, for example, when an evil nature appears in the substance of the organs and replaces the original nature, itself becoming, as it were, the original nature, and this does not cause pain, because such a phenomenon is not felt. The point is that the sensory organ must experience the influence of what is sensed, but a thing does not experience the influence of the state that owns it, unless it changes it, transferring it to another state; a thing is only affected by something opposite, coming from outside and changing the thing, transferring it to a different state. That’s why a patient with a tabes fever does not feel such a burning sensation as a patient with a one-day fever or a patient with a three-day fever feels, although the heat of a patient with a tabes fever is much stronger than that of a patient with a three-day fever, since the heat during tabes strengthens and constantly resides in the substance of the main organs, and the heat with a three-day fever, due to the proximity of the diseased juice, it covers organs that still have their natural nature. Thus, when the juice is removed from the organ, the organ remains of its former nature, and the heat in it is not stable, unless it has become too tightly attached and the disease has developed into tabes.

The disorder of the consonant nature of the organ occurs gradually and occurs in a healthy state. Here is an example that makes this more understandable: if a person is unexpectedly bathed in winter, then bathing in hot or even warm water will be disgusting and unpleasant for him, because the quality of his body is far from warm water and is opposite to it. Then a person gets used to it and begins to enjoy it, gradually moving away from the state of cold that affects him. Then, after he sits for some time in the inner bath, sometimes it happens that his body becomes hot with this water, and if he is unexpectedly doused with the same first water, a chill will creep through his skin, and the water will seem cold to him.

Since you now know this, we will say that, although one of the categories of causes of pain is the disorder of dissimilar nature, not every disorder of nature is explained by dissimilarity. Thus, hot causes pain by its essence, cold also by its essence, dry by its inherent property, and wet does not cause pain at all, for coldness and warmth are active qualities, and dryness and wetness are passive qualities, the essence of which lies not in so that one body acts thanks to them on another body, but that one body experiences the influence of another. As for dryness, it only causes pain due to its incidental quality, because it is followed by a cause from another category, namely, a violation of continuity, for dryness, due to strong contraction, is sometimes the cause of a violation of continuity.

As for Galen, Galen, if you really think about his teaching, believed that the essential cause of pain is nothing more than a violation of continuity. According to Galen, hot causes pain precisely because it breaks continuity, and cold also causes pain only because it is accompanied by a break in continuity. After all, the cold compacts and collects so strongly that particles of organs are necessarily drawn to the place where the compaction occurs and move away from the side from which the cold pulls them away. Galen expanded greatly on this topic and even made it clear in one of his books that all sensible things cause suffering in the same way, I want to say - they cause suffering by the separation of particles or the collection that is accompanied by separation. Thus, black in visible objects irritates because it strongly collects particles, and white because it strongly separates them; bitter, salty and sour things in the things being tasted irritate by excessive separation, and tart things by excessive contraction, which is necessarily accompanied by separation. The same goes for smell.

Loud screams are also annoying, separating particles due to the sudden movement of air in contact with the ear canal. However, correct judgment in this matter forces us to consider change of nature a category that in itself causes pain, although sometimes a violation of continuity occurs. A thorough explanation of this is not found in medicine, but in the physical part of philosophy, but we will point to an insignificant part of it and say: pain is the same in all particles of the painful organ, and the disruption of continuity is never similar in all particles; therefore, the presence of pain in particles free from disturbance of continuity does not arise from disturbance of continuity, but arises from a disorder of nature. And one more thing: the cold hurts where it compresses and collects, and where it is cold in general. And disruption of continuity from cold occurs not where it cools, but at the ends of the cooled area. And one more thing: pain is necessarily a sensation of the sudden impact of something unpleasant, since it is unpleasant, and therefore a sudden unpleasant sensation is painful. This definition is reversible, and therefore any unpleasant sensation is painful. Have you thought: if you feel cold, which upsets the nature, since cold upsets the nature, but does not cause, for example, a violation of continuity, is this an unpleasant sensation and is it, therefore, pain? From this we learn that a sudden change in nature is as much a cause of pain as a break in continuity. The pain increases the warmth and thereby causes pain after pain. After pain there remains something that gives the sensation of pain, but is not real pain. This is one of those sensations that goes away on its own, but the ignorant treat it and do harm.