Introduction - Spiritists still misunderstand the term "doctrinal purity". Some believe that doctrinal purity plasters Spiritism, preventing the development of its progressive feature (Kardec, Chapter I, and item 55, of "A Gênese" (The Genesis) [1]). However counterintuitive it may seem, the most important ingredient to develop Spiritism efficiently is precisely the doctrinal purity. To understand this, let us draw a parallel between the concept of "doctrinal purity" and the attitude of scientists regarding the progressive feature of Science.

What doctrinal purity is, and its importance regarding the Spiritist Movement, has already been discussed within Spiritist literature [2, 3]. As previously noted [3], the concept of "purity" of some "thing" has no value for the "thing" itself (which is pure by nature), but for whom employs it for a particular purpose. For example, it makes sense to say:" The water I am going to drink is pure," but it makes no sense in saying that "pure water is pure". The adjective doctrinaire refers only to the kind of purity that is being analyzed. Thus, it makes no sense to check if the Spiritist Doctrine is pure because this would be redundant! Doctrinal purity only applies to the Spiritist Movement since it represents the way people practice, experience and use Spiritism in their lives. Therefore, are do we know if everything we study, practice and experience, reflects the teachings of Spiritism? Is the water we drink pure?

The Spiritist Movement (SM) (ME - Movimento Espírita) is very much interested in the discoveries of Science and in particular of Physics. Therefore, it is wise to analyze how the progressive feature of Science develops. What we will further see is that the rigor of Science in its research represents the application of the concept of doctrinal purity in its development.

When people watch amazed the news about new discoveries in Physics, hardly do they know that Physics is extremely rigid and does not accept anything new before checking all its validation criteria.

The doctrinal purity in Physics - Therezinha Oliveira, when talking about the possibility of adding new insights and knowledge to Spiritism, says [2] that "... not without previously passing the sieve of reason and, whenever possible, experimentation ". Is this not exactly what physics scientists do, i.e., to go through the scrutiny of reason and experimentation? Literally, what physicists do is to follow "to the letter" what we may call "doctrinal purity in Physics" ! However, how can a science so progressive as Physics adopt the" doctrinal purity" in its criteria? The answer is simple. It is precisely because it applies all scientific rigor in its research criteria that the results of Physics have so much value! Likewise, as a true science, it is precisely adopting the "doctrinal purity" that Spiritism will progress striding much more than we can imagine today. It is not adopting with no criteria and reason esoteric concepts, pseudoscientific practices and all kinds of news that Spiritism will develop. Doctrinal purity in any Science, including the Spiritist Science, is nothing more than compliance with the methods, scientific rigor, theories, and paradigms of Science itself in the research work and development of new knowledge!

The misconception is caused by considering the concept of "doctrinal purity" as a factor of stagnation. In the full millennium of light of knowledge, the ME (SM) needs to mature its understanding about the real meaning of doctrinal purity. For that, let us analyze a little more the manner in which Science develops.

What gives credibility to a finding in any area of ​​knowledge, is the compliance with criteria, scientific rigor, and fundamentals of the respective area. In the area of Physics, physicists and scientists follow rigorous methods and concepts established by the theories and paradigms of Physics. If some scientist decides to use research methods of another area when investigating Physics concepts, it will have no scientific value. If some scientist decides to invent new methods without justifying them in terms of current concepts and methods, it will have no scientific value. Thus, new discoveries are only accepted in an area, if they are faithful to the concepts, methods, and criteria of the original paradigm of the respective scientific discipline. 

Why Higgs boson? - As an example, let us analyze one of the recent discoveries of Physics that drew media's attention: the Higgs boson. The magazine Science devoted a special space for several articles on the subject (including free access to some of them [4]). The so-called Standard Model of subatomic particles is considered one of the most comprehensive and successful theories of Physics, since it describes in a precise way the properties of the particles that make up matter, and the interaction forces between them (except gravity). However, one of these particles properties, not explained by theory, is mass. Forty years ago, Higgs proposed the existence of a field that would be responsible for the mass property of the particles. Since fields, according to Quantum Physics, are made of a type of particle called boson, responsible for this field, it took its name: Higgs boson. If this particle really existed, the mass of the particles could be explained by the Standard Model consistently. The concept of "doctrinal purity" in the discovery of the Higgs boson is evident in two ways. First, when it verifies that, even though the Standard Model supported the existence of this particle, physicists did not consider for granted the existence of the Higgs boson! This, then, according to the doctrinal purity of Physics, it is not enough to just make sense in theory, the existence of the Higgs boson needed to be verified experimentally and with all the scientific rigor determined by Physics.

Scientists from various areas have built a device costing over 5 billion dollars [4] to perform the experiments of particle collisions needed to observe the Higgs boson. However, the second way to understand the concept of doctrinal purity in Physics comes from the following. Since the collision phenomena, involved in the experiment, can be explained by other factors, it was necessary to repeat the collisions of particles per billion times and using more than one different method at the same time [5]. 

What is considered true in Physics - Based on the analysis and comparison of the results, it was possible to demonstrate that the Higgs boson is present in certain types of nuclear reactions with an error of 1 in ~ 300 million events! Only then, did physicists consider the existence of the Higgs boson! This is doctrinal purity applied to Physics! This is an example of the caution that Physics has before considering as true something new.

"It is therefore necessary to avoid letting yourself be seduced by appearances, both on the part of the Spirits, and men; ... it is necessary that everything be coolly examined, maturely weighed, confronted, and if we mistrust our own judgment, (...), it is necessary to call upon other people". (My emphasis in bold). Do not these words of Kardec, in a speech delivered on September 19, 1860 to the Spirits of Lion [6], express the exact position of doctrinal purity that Physics and all Science adopt? Therefore, the Spiritist Movement must value the doctrinal purity in its activities. The doctrinal purity shall help with precision the progressive feature of Spiritism.

To develop well the progressive feature of Spiritism, it is necessary: 1) to study thoroughly the basic works of Spiritism. 2) To study the works, mediunic or not, of well-recognized authors in the Spiritist movement, always checking if they actually do not conflict with the doctrinal fundamentals. 3) To avoid adding new grafts and innovations without meeting the test of reason and without proper demonstration, which, in turn, cannot be accomplished in a superficial way and without total mastery of the subject (see, e.g. the analysis presented in reference [7])? And 4) to follow the recommendation of Erastus (item 230 of the Book of Mediums [8]): "it is better to reject ten truths than to admit a single falsehood, one only erroneous theory". In other words, as described in the Introduction to The Gospel According to Spiritism [9]: "One only serious guarantee exists for the teaching of the Spirits: the conformity of the spontaneous messages, using a large number of mediums strangers to each other and in various places. (...) This universal proof is a guarantee for the future unity of Spiritism and shall void all contradictory theories. This is when, in the future, the criterion of truth shall be found". (My emphasis in italic and bold).

Finally, never forget that "what usually features a new revelation, when it really is one, is not the denial of the former, but precisely its confirmation of the fundamental steps that will support them". (Yvonne do Amaral Pereira [10].) 

Kardecian base and its importance - To conclude, we copy below the concern of the good spirits with respect to doctrinal purity and fidelity:

"Spiritism has its essential aspects based on a triple configuration. Let none be restricted in their expectations of construction and production. The one who becomes fond of science, let him cultivate it within its dignity. The one who devotes himself to philosophy let him enhance its postulates. And those who dedicate themselves to religion let them deify the aspirations, but Kardec's base must remain in everything and everyone, so that we do not lose balance on the foundations on which the organization is raised. (...)

It turns out, however, that we need to preserve spiritist basics, honor and sublimate them, or we will end up strangers to each other, or turn into corpses in regimentations, which shall mutilate our best wishes, and the movement of freedom converting us into closed sects, jailed on new interpretations and theologies, which would keep us within the conveniences of the lower plane and distance us from the truth. (...) 

(...) Allan Kardec, in the studies, reflections, activities, works, so that our faith will not become an hypnosis, whereby the power of darkness sets on the weaker minds, chaining them to centuries of illusion and suffering.

(...)

(...) "Let Allan Kardec be, not only believed or felt, proclaimed or manifested, our flag, but sufficiently lived, suffered, cried and held in our own lives. Without this foundation, it is difficult to forge the Christian-Spiritist character that this troubled world expects from us through unification" ["Unificação" (Unification)], Bezerra de Menezes' message, received by Chico Xavier on 04.20.1963, and published in the Reformador (Reformer), December 1975. (My emphasis in bold and italic). 

Fidelity to doctrine is essential - "The program that you have established for this five-year period is quite significant, because it came from the High, where it was elaborated and you clothed it with skilled considerations applicable to this present time. This is the time, children of the soul. Do not prevaricate by being seduced by the singing of the sirens of illusion. Fidelity to doctrine is what is imposed on us, celebrating the one hundred and fiftieth anniversary of the basic work of the Spiritist Codification. Do not allow bizarre additions to be placed in the form of appendices that avert the less enlightened regarding the essential purpose of the doctrine. (...) Be faithful, remaining deeply connected to the spirit of Spiritism in the same way you received it from the immortals through the eminent Codifier". ("O Meio-Dia da Nova Era" (The Midday of the New Era), message by Bezerra de Menezes received by DP Franco in April 12, 2007 and published in the "Reformador" (Reformer), June 2007. (My emphasis in bold).

"These current times call us to faithfulness to the projects of the Spirit of Truth, to be attentive to not forsake the genuinely spiritist work, occupying valuable time with verbiage and disputes, situations and issues that, reportedly, have nothing to do with our cause, because they are not a matter for Spiritism. ["Definição e trabalho em tempos difíceis" (Definition and work in difficult times)], "message by Camilo, received by Raul Teixeira on 11/11/2005 published in the Reformador (Reformer), January 2006. (My emphasis in bold).

References: 

[1] A. Kardec, A Gênese (Genesis), Publisher FEB, 36th Edition, Rio de Janeiro (1995)

[2] T. Oliveira, "Pureza Doutrinária" ("Doctrinal Purity"), FidelidadESPÍRITA 112, 15 (2012).

[3] A. F. da Fonseca, “O Que Seria Pureza Doutrinária Segundo o Espiritismo?” ("What would Doctrinal Purity be According to Spiritism?"), Bulletin GEAE n. 529, September 15, (2007), and O Consolador (The Comforter) 162, June 13 (2010) Reprinted in: http://www.oconsolador.com.br/ano4/162/especial.html

[4] Log, for example, the links: http://www.sciencemag.org/site/special/btoy2012/,

http://www.sciencemag.org/content/338/6114/1524.full

[5] M. Della Negra, P. Jenni and T. S. Virdee, "Journey in the Search for the Higgs Boson: The ATLAS and CMS Experiments at the Large Hadron Collider", Science 338, 1560 (2012). Accessible via link: http://www.sciencemag.org/content/338/6114/1560.full

[6] A. Kardec, O que é o Espiritismo (What Is Spiritism), Publisher FEB*, Rio de Janeiro (2006).

[7] A. F. da Fonseca, "Scientific Review of Apometry" O Consolador (The Comforter) 289, December, (2012). Access the link: http://www.oconsolador.com.br/ano6/289/especial.html

[8] A. Kardec, O Livro dos Médiuns (The Book of Mediums), Ed FEB, 1st Edition, Rio de Janeiro (2008).

[9] A. Kardec, O Evangelho segundo o Espiritismo (The Gospel According to Spiritism), Publisher FEB, 112th Edition, Rio de Janeiro (1996).

[10] Several Spirits, Cristiano Emanuel's psychography, O Zelo da tua casa (The zeal of thine house), Publisher Allan Kardec, Campinas (2009).

* FEB Federação Espírita do Brasil (Brazilian Spiritist Federation)