Regarding to the spiritist doctrine, the theory was born from observation

 
It is always worth remembering as the spiritist doctrine was developed so that all who write about Spiritism and especially those who maintain exchanges with the spiritual plane have a little more careful with thoughts and ideas that come up time and again in our midst, in disagreement with the work that Allan Kardec bequeathed us.

In the opening chapter of his book The Genesis, Kardec reported to the subject. What the reader will see below is a synthesis of what he wrote about the work he has done in his coding task of spirit teachings.

As a means of development, spirit science proceeded and it should proceed identically to the adopted positive sciences by applying the experimental method. New facts that cannot be explained by the known laws are presented; Spiritism notes them, compares and analyzes, reassembling from effects to causes, comes to the law that governs, then deducts them the consequences and seeks useful applications. Allan Kardec did not establish, therefore preconceived theory and thus not presented as hypotheses the existence and intervention of spirits, nor perispirit, or reincarnation, or any of the principles of the doctrine. He concluded through spirits existence when that existence highlighted evident from observation the facts, proceeding in the same way as other principles. There were not, therefore, the facts that have come after to confirm the theory: the theory is that subsequently came to explain and summarize the facts. It is therefore strictly accurate to say that Spiritism is a science of observation and not the product of imagination.

As we know, the sciences have made important progress only after their studies were based on the experimental method, until then, it was thought that this method was applicable only to matter, while it is also to the metaphysical things. That was an important discovery which surely prevented the spiritist doctrine to soak itself of ideas without any support experimentation.
Kardec mentions, concerning the matter, in the example below.

It occurs in the spirits world a singular fact that surely no one there had suspected: the spirits there who do not consider themselves dead. Now the superior spirits, who know perfectly that, did not come to say in advance: "There are spirits who still believe live terrestrial life, which retain their tastes, habits and instincts." Instead, it was caused the manifestation of spirits in this category to Kardec and his companions scattered throughout various parts of the globe observe them.

Having seen spirits up unsure of their status, or even be saying they are from this world, judging themselves applied to their ordinary occupations, it was deduced the rule. The multiplicity of analogous facts showed that the case was not unique or exceptional, that was one of the stages of spirit life. We could then study all varieties and causes of this singular illusion, recognizing that this fact is especially a characteristic of Spirits little bit ahead morally and peculiar to certain genera of death. It was realized also that this situation is always temporary, although can last weeks, months and even years. It was thus that the theory was born from observation. And the same was true with respect to all other principles of the doctrine.

That was surely one of the reasons why Jose Herculaneum Pires wrote these words: "Touch is the most common form of verification of truth. It uses touch in Medicine, Agriculture, Jewellery - which is known as the function of touchstone - and in practically all human activities. It was through the touch of his fingers in the wounds that Thomas recognized the legitimacy of the apparition of the risen Jesus. In Spiritism the touchstone is Kardec's work." (In Time of Touch, in The Stone and the Tares.)

The other reasons why Kardec's work is considered by the Herculaneum Pires the touchstone on Spiritism matter, the reader will see reading the book we have referred.