Mental strength covers two forces, for which it is, as it were, a generic concept. One of them is the comprehending force, the other is the driving force. Comprehending force is, as it were, a generic concept for two forces: the force that comprehends outside, and the force that comprehends within. The force that perceives externally is the force of sensation, and it is, as it were, a generic concept, according to some, for five, according to others, for eight forces. If they count five, then it will be the power of vision, the power of hearing, the power of smell, the power of taste and the power of touch, and if they count eight, then the reason for this is that most researchers see many forces in touch, more precisely, four forces. They associate each of the four kinds of tangible things with a special power, although this power acts in conjunction with another power J in the sensory organ, as taste and touch in the tongue, sight and touch in the eye. But testing the truth of this is the work of the philosopher.
The force that comprehends within, that is, the animal force, is, as it were, a generic concept for the five forces. One of them is the force that is called the general feeling and imagination. Doctors consider general feeling and imagination to be one force, and philosophical researchers - two. The general feeling is the feeling by which all sensible things are comprehended. It experiences the effect of their images, and these images are collected in it. And the imagination is the power that preserves the images of sensible things after they have been collected, and retains them when they are hidden from the senses. Of these two forces, the perceptive force is not identical to the preserving force. Establishing the truth in this matter is also the work of a philosopher.
Be that as it may, the location of these forces and the source of their action is the anterior ventricle of the brain.
The second force is the force that doctors call the thinking force, while researchers sometimes call it the imagining force, and sometimes the thinking force. If it is used by the animal force of instinct, which we will talk about later, or it begins to act on its own, it is called “imagining”, but if the logical force appeals to it and spends it on something that benefits from it, then it is called "thinking power" The difference between this force and the first, whatever it may be, is that the first perceives or stores the sensible images that flow to it, while the second disposes of the images stored in the imagination, making a combination or division over them, and calls forth various images , similar to what is delivered by sensation, or different from them, such as the image of a flying man, mountains made of emerald, and the like.
As for the imagination, this power calls upon it only to perceive impressions from sensation. The seat of this force is the middle ventricle of the brain.
The above-mentioned force is an instrument of a force that in reality is internally comprehending in an animal, that is, instinct. Instinct is the force that determines in the animal’s mind, in a non-logical way, that the wolf is an enemy, that the cub is dear, that the one who takes care of the food is a friend, and one does not run away from it. Hostility and love are not tangible things, and the animal does not comprehend them by feeling; consequently, love and enmity are judged and comprehended by another force, although this comprehension is not logical. However, this will necessarily be comprehension, although not logical. Man also uses this power in many of his decisions and in this follows the path of an animal incapable of logical thinking.
This power differs from imagination, for imagination fixes sensations, and instinct judges sensible things with the help of intangible essences. Instinct also differs from the force that is called “thinking” or “representing,” for the actions generated by instinct are not accompanied by any judgment, whereas the action of the thinking force is accompanied by some judgment; or rather, it represents a series of judgments. Moreover, the action of the imaginative force is combined in sensible things, and the action generated by instinct is a judgment about the sensible, resulting from entities standing outside the sensible. Just as sense in animals judges about perceived images, so instinct judges about those essences of these images that reach instinct, but do not reach sense.
There are people who, metaphorically speaking, call this force imagination. This is permissible for them, because there is no point in arguing about names, but it is necessary that the meaning of the definitions and the difference between things be clear.
The doctor does not seek to understand this force, since the harm from its actions is a consequence of the harmful actions of other forces that functioned before, such as ideas, imagination, memories, which we will talk about later. The doctor considers only those forces which, when their actions become harmful, cause disease. If the action of a force is followed by harm, which is the result of harm caused by the action of a force that functioned before, and this harm is generated by bad nature or a bad combination of particles in any organ, then it is enough for the doctor to know that this harm followed due to the bad nature of the given organ or a bad combination of particles to
correct it with treatment or beware of it; he is not obliged to know what is the state of the force to which something reaches only through an intermediate link, if he knows the state of the force to which the same thing reaches directly.
The third force that doctors talk about - in philosophical research it turns out to be the fifth or fourth - is the force that preserves or remembers. It serves as a repository of the essences of sensed things reaching the mind, but not their images perceived by the senses, and its place of residence is the posterior ventricle of the brain. Here it seems appropriate to philosophically consider the question whether the preserving force and the remembering force, which brings back the impressions of the mind that have disappeared from memory, are one force or two forces, but this is not necessary for the doctor, since the damage that befalls any of these forces is akin to between themselves; these are lesions that affect the posterior ventricle of the brain and belong to either the natural or particle combination category.
As for the remaining power from the comprehending powers of the soul, this is the logical power inherent in man. But since the power of instinct is not subject to consideration by doctors for the reason that we have stated, then they should certainly not consider the power of logic. On the contrary, their consideration is limited only to the actions of the three mentioned forces, no more.
As for the driving force, it is that force which stretches the tendons and weakens them; it moves organs and joints, releasing them and retracting them. The passage for this force is in the nerves adjacent to the muscles. This kind of force is divided into categories according to the categories of the sources of movement, so that in each muscle there appears a driving force of a different nature, which follows the greatness of the mind, causing the volitional impulse.