Handbook of epistemology/Science of the soul or science of matter?
Cognition is the production and use of internal representations that prepare for action.
A common misconception is that a science should be materialistic to be truly a science, which leads to the rejection of the old Aristotelian definition of psychology, the science of the soul.
It must be remembered that this prejudice, or others like it, on what science should be, are obstacles to the development of scientific knowledge. To do scientific work it is neither necessary nor desirable to tie one's hands in advance with such a priori, looking honestly for truths and their proofs is enough. No other principle has priority over this one.
To speak of souls is first of all to speak of ourselves, of what we are, of what we experience when we perceive, imagine, feel, think, want or during any other inner activity of which we are aware. We do not know very well what the soul is or why it lives with a body, but we know it is there, and we can work honestly to develop true knowledge about it. It does not take more to justify this venerable expression, science of the soul.
The alliance of the soul and the body is so mysterious that we do not even know if we express it correctly: must we say that we are souls and that we have a body? Or that we are bodies? Inhabited by a soul? Is the soul only a way of being of the body?
But it is not necessary to solve these mysteries to progress in knowledge.
One thing is certain from the point of view of empirical science, that to know souls, we can and must observe their bodies. To study souls, as a scientific observer or experimenter, is always to study bodies.
Is the science of matter in principle sufficient to explain our existence as conscious beings? We do not know. We may believe that consciousness emerges from the cerebral life, but we do not know how to explain it. Nerve impulses are produced by electrical currents in neurons and across their membranes. These are very ordinary ionic currents. Nothing suggests that they must be the messengers of the spirit. And if one holds to a strictly materialistic cosmology - only atoms and emptiness - it seems that the Universe should be without souls. Atoms do not need souls to be atoms.
We do not know how the life of the body brings out that of the soul, we only know that a soul needs its body to be what it is. All the faculties of the soul depend on its body. To see requires eyes, and a brain that interprets visual information. To act requires hands and feet, or other effectors, and a brain that controls them. To remember, we have to keep records somewhere in our head. Emotions are affections of the body as much as of the soul. Thought could not exist without the word, and therefore without the tongues that make it heard. It is as if bodies give souls the means to do what they do. We know what they are by understanding what they do with their bodies. The more we know about the body, especially the brain, the more we can understand what they are.
It is not necessary to know the functioning of one's brain, nor even to know that we have one, to know oneself as a soul, because the soul is always able to reflect: when we see, we do not only know the object seen, we also know ourselves. When we see it, we know we see it. The same goes for all conscious activities. When we remember, we know we remember. When we want, we know we want. We can not live consciously without knowing we live consciously. Through reflection the soul is directly informed of its own activity. It can not be a soul without knowing itself so. Its nature is to be a constant witness of itself.
Because it is natural and spontaneous, it is sometimes believed that self-knowledge acquired through reflection has no place in science. It would only be prescientific, as if science needed much more sophisticated means to really be science. But it is a misconception on the nature of science. How could we develop real knowledge if we give up reflection? We could not take a single step forward. Even scientists who claim that reflective knowledge is unscientific have not given up reflection, or they could not even think. On this subject it must be remembered that science fires any wood. All sources of knowledge are a priori welcome. All thoughts, observations, principles, definitions, hypotheses, arguments, reasonings, objections, are welcomed and encouraged, provided that it is an honest search for truths and proofs. Scientific honesty requires only that one voluntarily submit oneself to criticism, not that one renounces one's natural faculties.
All faculties of the soul rely on its ability to produce and use representations. Visual images are representations of objects seen. When we imagine, we represent in our mind what we imagine. When we want, we form representations of what we want. Even when we feel, we represent the beings who provoked our emotions. The study of representations seems to be a good starting point for studying the faculties of the soul. But the definition of the concept leaves us on our hunger, because anything can be considered as a representation. To be a representation it is enough to carry information, whatever their nature and the way they are carried, on another being. Since all beings always carry such information, they can always be considered as representations. To be able to interpret the signals they carry is enough for them to serve as representations. It is precisely this point which is essential. Souls use the representations they produce to act on their environment and on themselves. But the ability to use representations is not reserved for souls. Living beings, even the simplest, and robots, also use internal representations to act.
Cognition is the production and use of internal representations that prepare for action. Cognitive sciences are all disciplines concerned with the study of cognition: psychology, neuroscience, ethology, artificial intelligence, robotics, epistemology, linguistics ...
The use of representations is not enough to explain the existence of consciousness - robots use representations without being aware of what they represent - but it is still fundamental to know the souls, because they could not to be what they are if they did not use the representations they produce. To exist, they need a body that makes them capable of producing representations that prepare them for action. A soul gives itself representations, it is what represents to itself, what perceives and imagines. To seek the soul in the brain is to look for the representations it gives itself. Studying the ability of bodies to produce and use representations is therefore a good approach to understanding the faculties of the soul.
To use representations, one must be able to act, one must be an agent, that is to say an animated body: a living being or a robot. An agent is always a system that interacts with its environment through sensors and effectors (Turing 1936, Russell & Norvig 2010).
The sensors (the sensory organs) are connected by a nervous system (the brain, the spinal cord ...) to the effectors (the muscles, the excretory glands ...) in order to produce an intelligent behavior (Churchland & Sejnowski 1992, Gazzaniga & Ivry 2001).
Sensory perception consists of producing internal representations from the signals provided by the sensors. It prepares for action by making the agent able to adapt to its present environment. But the senses are not the only sources of internal representations. All forms of perception and imagination are ways of producing internal representations that prepare for action.