Pain perception and vision 

We already know from the last century which are the neurons involved in the perception of pain, and visual images. The neurologist knows the entire route covered by the sensation of a sting in the skin and which causes pain. The same goes for the objects registered by the retina, and is image coding by the brain. What we already know, as well, is that this entire route of nerve pathways represents only a small percentage in the two phenomena, pain perception, and vision of the objects.

In both cases, the most important is the mental process that interprets pain and gives meaning to the images. Neurologists say that this mental phenomenon depends on a number of factors. The way we express our pain and give meaning to what we are seeing is strongly linked to our culture, personality, previous experiences, memories, and environment. In fact, both pain and vision are mental processes of interpretation, or, as the more liberal neurologists say, it is all a "personal opinion."

It is amazing what we can learn in The Book of Spirits that teaches us how these two phenomena affect the Spirit: "The memory of pain, which the soul keeps, can be very painful." "The pain you feel is not therefore a physical pain: it is a vague inner feeling ... because the pain is not localized and it is not produced by external agents" (The Book of Spirits, question 257).

Regarding the vision (questions 245, 246 and 247), "it lies in all of it. They see for themselves, without the need of external light. As the Spirit carries himself to wherever he wants, with the speed of thought, it can be said that it sees everywhere at the same time".

Neurology should confirm in the future these two data, passed by Kardec to us for study. Initially, Neurology shall need to consider the mind as synonymous of the soul. 

Time 

In Newton's mechanistic theory, time was considered an absolute magnitude; otherwise, the calculations that mediate the distances between the planets would have been wrong. Einstein, however, pervaded that relation, proposed the relativity of time, increasing the accuracy of those measurements.

Regardless of scientific propositions, philosophers always speculated about the nature of time. Henri Bergson gave us a poetic statement that "Time of consciousness is not the same as Time of Science." According to common sense, we have all found that the passage of time is circumstantial. Just consider the year for school students, the months for pregnant woman, the days for those who pay rent, the hours for those who have an appointment, the minutes for the train to pass, and the milliseconds for Formula 1. 

Neurology considers the notion of time as a clearly mental experiment, occupying different areas of the brain simultaneously.

Kardec received from the Spirits the information that "time is only a relative measure of the succession of transitory things; eternity is not susceptible of any measure, in terms of duration; for eternity there is no beginning or end: all is the present" (Genesis, Chapter VI, item 2). We need to highlight this statement of extraordinary complexity and consequences: for the Spirit everything is the present. 

The properties of matter 

In The Book of Spirits (questions 29 to 34), we learned about the existence of a single primitive element that origins all the properties of matter. Being attached to the material reality of our world, we can identify the chemical and physical properties of gross matter that makes up our physical dimension. However, the primitive element (cosmic fluid), which expands throughout the universe, has special properties that we still do not know and that give the material the ability to experience all the changes and acquire all properties. Moreover, the Spirits say, "that everything is in everything."

Only then can we understand the extraordinary expressions of the psychic phenomena of physical effects when the laws of ponderability are pervaded. A stone, as solid as we know it, can cross a roof and settle inside a closed cabinet. The cosmic fluid carries out these changes in the properties of matter, and which are still unknown by Science, because it ignores the principles of its operation.

We also do not have the power yet, to understand the extent of the spiritual connection that this universal fluid allows the matter to submit to the thought of God. In Genesis (Chapter II), the Spirits say, "every atom of this fluid, if thus we can express ourselves, having the thought, i.e., the essential attributes of deity, and being the same fluid everywhere, everything is subject to its intelligent action, its foresight, to its care." "The whole of nature is immersed in this divine fluid." 

Creative thinking and fixed ideas 

Berkeley's immaterialism (Donald George Berkeley, Irish philosopher, 1685-1753) proposed "to exist is nothing but to be perceived." "Matter only exists when it is perceived."

"Visual perceptions are not of external things, but simply ideas in the mind." Socrates stated, "Things exist due to how we perceive them." In The Book of Spirits (question 32), the Spirits teach that the qualities of the bodies ("flavors, smells, colors, poisonous or wholesome qualities") only exist due to the disposition of the organs intended to perceive them. It is like this that the Neurology today arrangement of organs for perceiving them. Nowadays, Neurology, in accordance with this line of thinking, understands the perception we have of an object that reaches our senses.

Present proposals are stating that matter only manifests itself as a mental interaction. However, neurologists still fail to understand the nature of mental creation, except when a behavior expresses an answer to a sensory stimulus. Intuitive thinking, or abstract thinking, is far from any laboratory experiment.

In Spiritism, we learn that thinking proceeds from the Spirit, source of creative energy that uses the brain as an instrument of its ideas.

Regarding the thinking area, the Spirits added unprecedented knowledge, and so extraordinary that even today Science even has tools to study it. The Spirits say that the thought acts on the universal fluid creating on it "fluidic images." The thought is reflected in our perispiritic involucres, as in a mirror, and there somehow it is photographed.

"This fluid (perispiritic) is not the thought of the Spirit; it is, however, the agent and the intermediary of that thought. Considering that it is the agent that transmits the thought, the though transmitted impregnates the agent too." (Genesis, Chapter II, item 23).

Hence, the seriousness of letting ourselves be enslaved by persistent thoughts that imprison us, the desires that disturb us, the unjustified revenges, the hatred that never fades, the passions that unbalance us, and the projects that we cannot reach. They are all "fixed ideas," that "materialize" in our mental sphere, creating "ideas-forms", "fluidic images", "mental miasma" that justify the numerous expressions of neuroses and psychoses common in human psychopathology. 

Vitalism 

Claudius Galen, physician of the second century, stated that there were forces of attraction and repulsion to keep the organs functioning. For him, life would be maintained by an immaterial element called vital pneuma, in the heart, spreading through the blood existing in the veins. In the brain, it is transformed into animal pneuma, allowing us to react to stimuli of the senses, and in the liver, it is transformed in natural pneuma with the property to digest food. Galen's theories have been accepted for over twelve centuries.

In the early sixteenth century, Georg Stahl revived the vitalism theory defending the existence of a "sensitive soul" necessary for the maintenance of life. On this occasion, Stahl suffered a fierce opposition from the mechanistic theories, defended mainly by Frederich Hoffman. Excluding the existence of the soul, Hoffman saw in the vital processes only phenomena of fermentation of substances and combustion of gases, thus explaining digestion and breathing.

The spiritual doctrine strongly revives the vitalism theory. It teaches that there is an immaterial element that sustains life in organic matter (The Book of Spirits, questions 60 to 67), and "not to mention the intelligent principle, which is a separate issue, there is in the organic matter a special principal, inapprehensible and that cannot yet be defined: the vital principle" (Genesis, Chapter X, item 16). 

Sleepwalking 

Nowadays, sleepwalking no longer arouses the same interest and prestige it enjoyed in the time of Kardec. Treaties with massive casuistic were written by Ambrose-August Liébeaut, Abbot Faria and Charles Richet. The Charcot school in Paris accepted it as a form of therapy, used on their hysterical patients.

Kardec informs having studied sleepwalking in all its phases for 35 years (The Book of Spirits, Introduction). In the same book, he writes several pages making a "theoretical summary of somnambulism, from ecstasy and second sight." He makes it clear that "for Spiritism, sleepwalking is more than a psychological phenomenon; it is a projected light on psychology. This is where you can study the soul, because this is when it shows itself unclosed."

In that excerpt, Kardec discusses about natural and magnetic somnambulism and emphasizes that clairvoyance is an attribute of the soul, allowing the sleepwalker to see everywhere where his soul is carried. In this view at a distance, "the sleepwalker does not see the things from where his body is, as if through a telescope. He sees them present, as if he is in the place where they exist, because his soul, in reality, is there." (The Book of Spirits, issue 455). 

Sleep and dreams 

We already know a lot about sleeping physiology. It occurs in rhythms with certain standards that are identified by EEG. Age, gender, the environment, the food, the profession are part of the numerous factors that influence the quantity and quality of sleep. We already know how much we need it, but we still cannot say all about the reason why we really need to sleep. Dreams are clearly linked to experiences during the day, they have an intimate relation with the acquisition of memories, but we also are unaware of its real meaning.

Freud claimed to have noticed that his patients sought him not only to make their complaints, but also to report their dreams. This aroused in him the idea that dreams have some hidden meaning. His book "The Interpretation of Dreams," 1900, triggered the most extraordinary revolution regarding the human mind. Dreams reveal an unsuspected content, since they signal desires contained in the unconscious.

Plato in his "Republic" anticipated Freud by stating that during the sleep the soul tries to withdraw from external and internal influences, which are expressed in dreams, desires, which usually do not express themselves in the waking state.

Kardec, in The Book of Spirits starts the chapter on the Emancipation of the Soul studying sleep and dreams. Spirits clarify that during sleep the soul sees itself partially released from the body and "goes into more direct relation with the Spirits." In such circumstances, the soul can keep in touch with familiar Spirits that guide, advice and become aware of its past and sometimes of the future. This is a field for future research, which needs to be developed and confirmed in the Spiritist circles. 

Deserved tribute 

We have approached fourteen topics of relevant scientific interest taken from two basic of the Spiritist Coding. After a century and a half, some of their claims are pending approval from official Science, while others are gradually being confirmed. For some time now, the Spiritist circles are devoting themselves more systematically to the study of Spiritism, as a science, together with its philosophical content, and its moral consequences. Only in this way, can we make human Science record the name of Allan Kardec as one of its leading figures. We need to do a tribute to Allan Kardec for his scientific legacy.