In explaining mental pictures, philosophers have found the chief difficulty in the fact that we ourselves are not the outer things, and yet our mental pictures must have a form corresponding to the things. But on closer inspection it turns out that this difficulty does not really exist. We certainly are not the external things, but we belong together with them to one and the same world. That section of the world which I perceive to be myself as subject is permeated by the stream of the universal cosmic process. To my perception I am, in the first instance, confined within the limits bounded by my skin. But all that is contained within this skin belongs to the cosmos as a whole. Hence, for a relation to subsist between my organism and an object external to me, it is by no means necessary that something of the object should slip into me, or make an impression on my mind, like a signet ring on wax. The question: “How do I get information about that tree ten feet away from me?” is utterly misleading. It springs from the view that the boundaries of my body are absolute barriers, through which information about things filters into me. The forces which are at work inside my body are the same as those which exist outside. Therefore I really am the things; not, however, “I” in so far as I am a percept of myself as subject, but “I” in so far as I am a part of the universal world process. The percept of the tree belongs to the same whole as my I. This universal world process produces equally the percept of the tree out there and the percept of my I in here. Were I not a world knower, but world creator, object and subject (percept and I) would originate in one act. For each implies the other. In so far as these are entities that belong together, I can as world knower discover the common element in both only through thinking, which relates one to the other by means of concepts.
The most difficult to drive from the field are the so-called physiological proofs of the subjectivity of our percepts. When I exert pressure on my skin I perceive it as a pressure sensation. This same pressure can be sensed as light by the eye, as sound by the ear. An electric shock is perceived by the eye as light, by the ear as noise, by the nerves of the skin as impact, and by the nose as a phosphoric smell. What follows from these facts? Only this: I perceive an electric shock (or a pressure, as the case may be) followed by an impression of light, or sound, or perhaps a certain smell, and so on. If there were no eye present, then no perception of light would accompany the perception of the mechanical disturbance in my environment; without the presence of the ear, no perception of sound, and so on. But what right have we to say that in the absence of sense organs the whole process would not exist at all? Those who, from the fact that an electrical process calls forth light in the eye, conclude that what we sense as light is only a mechanical process of motion when outside our organism, forget that they are only passing from one percept to another, and not at all to something lying beyond percepts. Just as we can say that the eye perceives a mechanical process of motion in its surroundings as light, so we could equally well say that a regular and systematic change in an object is perceived by us as a process of motion. If I draw twelve pictures of a horse on the circumference of a rotating disc, reproducing exactly the attitudes which the horse's body successively assumes when galloping, I can produce the illusion of movement by rotating the disc. I need only look through an opening in such a way that, in the proper intervals, I see the successive positions of the horse. I do not see twelve separate pictures of a horse but the picture of a single galloping horse.
The physiological fact mentioned above cannot therefore throw any light on the relation of percept to mental picture. We must go about it rather differently.
The moment a percept appears in my field of observation, thinking also becomes active through me. An element of my thought system, a definite intuition, a concept, connects itself with the percept. Then, when the percept disappears from my field of vision, what remains? My intuition, with the reference to the particular percept which it acquired in the moment of perceiving. The degree of vividness with which I can subsequently recall this reference depends on the manner in which my mental and bodily organism is working. A mental picture is nothing but an intuition related to a particular percept; it is a concept that was once connected with a certain percept, and which retains the reference to this percept. My concept of a lion is not formed out of my percepts of lions; but my mental picture of a lion is very definitely formed according to a percept. I can convey the concept of a lion to someone who has never seen a lion. I cannot convey to him a vivid mental picture without the help of his own perception.
Thus the mental picture is an individualized concept. And now we can see how real objects can be represented to us by mental pictures. The full reality of a thing is given to us in the moment of observation through the fitting together of concept and percept. By means of a percept, the concept acquires an individualized form, a relation to this particular percept. In this individualized form, which carries the reference to the percept as a characteristic feature, the concept lives on in us and constitutes the mental picture of the thing in question. If we come across a second thing with which the same concept connects itself, we recognize the second as belonging to the same kind as the first; if we come across the same thing a second time, we find in our conceptual system, not merely a corresponding concept, but the individualized concept with its characteristic relation to the same object, and thus we recognize the object again.
Thus the mental picture stands between percept and concept. It is the particularized concept which points to the percept.
The sum of those things about which I can form mental pictures may be called my total experience. The man who has the greater number of individualized concepts will be the man of richer experience. A man who lacks all power of intuition is not capable of acquiring experience. He loses the objects again when they disappear from his field of vision, because he lacks the concepts which he should bring into relation with them. A man whose faculty of thinking is well developed, but whose perception functions badly owing to his clumsy sense organs, will just as little be able to gather experience. He can, it is true, acquire concepts by one means or another; but his intuitions lack the vivid reference to definite things. The unthinking traveler and the scholar living in abstract conceptual systems are alike incapable of acquiring a rich sum of experience.
Reality shows itself to us as percept and concept; the subjective representative of this reality shows itself to us as mental picture.
If our personality expressed itself only in cognition, the totality of all that is objective would be given in percept, concept and mental picture.
However, we are not satisfied merely to refer the percept, by means of thinking, to the concept, but we relate them also to our particular subjectivity, our individual Ego. The expression of this individual relationship is feeling, which manifests itself as pleasure or displeasure.
Thinking and feeling correspond to the two-fold nature of our being to which reference has already been made. Thinking is the element through which we take part in the universal cosmic process; feeling is that through which we can withdraw ourselves into the narrow confines of our own being.
Our thinking links us to the world; our feeling leads us back into ourselves and thus makes us individuals. Were we merely thinking and perceiving beings, our whole life would flow along in monotonous indifference. Were we able merely to know ourselves as selves, we should be totally indifferent to ourselves. It is only because we experience self-feeling with self-knowledge, and pleasure and pain with the perception of objects, that we live as individual beings whose existence is not limited to the conceptual relations between us and the rest of the world, but who have besides this a special value for ourselves.
One might be tempted to see in the life of feeling an element that is more richly saturated with reality than is the contemplation of the world through thinking. But the reply to this is that the life of feeling, after all, has this richer meaning only for my individual self. For the universe as a whole my life of feeling can have value only if, as a percept of my self, the feeling enters into connection with a concept and in this roundabout way links itself to the cosmos.
Our life is a continual oscillation between living with the universal world process and being our own individual selves. The farther we ascend into the universal nature of thinking where in the end what is individual interests us only as an example or specimen of the concept, the more the character of the separate being, of the quite definite single personality, becomes lost in us. The farther we descend into the depths of our own life and allow our feelings to resound with our experiences of the outer world, the more we cut ourselves off from universal being. A true individuality will be the one who reaches up with his feelings to the farthest possible extent into the region of the ideal. There are men in whom even the most general ideas that enter their heads still bear that peculiar personal tinge which shows unmistakably the connection with their author. There are others whose concepts come before us without the least trace of individual character as if they had not been produced by a man of flesh and blood at all.
Making mental pictures gives our conceptual life at once an individual stamp. Each one of us has his own particular place from which he surveys the world. His concepts link themselves to his percepts. He thinks the general concepts in his own special way. This special determination results for each of us from the place where we stand in the world, from the range of percepts peculiar to our place in life.
Distinct from this determination is another which depends on our particular organization. Our organization is indeed a special, fully determined entity. Each of us combines special feelings, and these in the most varying degrees of intensity, with his percepts. This is just the individual element in the personality of each one of us. It is what remains over when we have allowed fully for all the determining factors in our surroundings.
A life of feeling, wholly devoid of thinking, would gradually lose all connection with the world. But man is meant to be a whole, and for him knowledge of things will go hand in hand with the development and education of the life of feeling.
Feeling is the means whereby, in the first instance, concepts gain concrete life.