The scientific guidelines for all projects presented on this website are the following:
1. Appeal for a culture of discussion which strives for neutrality – or: Polemics in the context of near-death research as a result of a lack in scientific discourse ability.
2. To speak the unspeakable – basic problems of a scientific examination of near-death experiences
3. Differentiation of varying approaches and explanations
4. Interdisciplinary research into ‚near-death experiences‘ and the ‘character of scientific revolutions’
A detailed description of these guidelines can be found shortly in the preliminary considerations regarding the history of science and the epistemology of the monograph E. E. Popkes, Erfahrungen göttlicher Liebe, Band 1: Nahtoderfahrungen als Zugänge zum Platonismus und zum frühen Christentum, Göttingen (Vandenhoeck & Ruprecht) 2017, 22-73 (an english translation will follow soon).
1. Appeal for a discussion culture which strives for neutrality – or: Polemics in the context of near-death research as a result of deficient scientific discourse abilities. Before outlining different approaches to interpretations and explanations of near-death experiences, it is important to realise a problem concerning the epistemology and scientific theory. In the context of near-death research a certain degree of polemics and personal defamation is observable, which is not tolerable. This may be because the examinations of death resp. of the question of any life after the bodily death do not only touch a level in the scientific discussion, but also the personal existence of those discussing. On the other hand those polemics may be traced back to the involvement of different areas of research in the discussion, which leads to a competition of very contrary professional expertises. Nevertheless it has to be stated that on the level of scientific communication, polemics have neither meaning nor function. Polemics often emerge in those situations in which personal and factual levels are not correctly differentiated. A lot of conflicts date from the personal involvement and vanities or a lack of scientific reflective faculty. Or, to use the terminology which will be explained in the following passages: In the context of a scientific debate about the phenomenon near-death experiences, it has to be possible that representatives of descriptive, religious-ontological, sceptical or reductionist-materialistic or parascientific positions communicate their views to each other without any polemic attacks or personal defamations. On a scientific level of communication it cannot and must not be the goal for individual positions to try and impose their views on other participants missionarily. It is more about exploring the different grades of plausibility of contrary approaches. Most of all, polemics prevent an interdisciplinary communication of different professional expertises a single researcher cannot possess but which is of central importance for further studies.
2. To speak the unspeakable – basic problems of a scientific examination of near-death experiences. A lot of people talking about their near-death experiences emphasize the fact
that those experiences were the most intense and consequential experiences of their lives. Nevertheless, it would be impossible for them to express their experiences in an appropriate way. This
is especially true of the fact that a lot of people having had near-death experiences claim for themselves to have communicated with other people or beings on a non-verbal level during those
experiences. How can inappropriate reports become a subject of scientific research? This basic problem, concerning the epistemology and theory of science, has to be kept in mind during any
examination of near-death experiences. The problems increase even more if one thinks about the consequences of this premise. By now, a lot of empirical surveys and documentations of near-death
experiences are available, which have been conducted in part in very disparate cultural and geographical contexts. The linguistic and intellectual prerequisites of the people affected can differ
significantly. The methodical premises and categories of interpretation which underlie the empirical surveys are very heterogeneous from time to time. It is important to consider a methodical
problem, namely that a grid of given questions designed by the authors of the respective survey can already have suggestive traits and therefore prefigure the outcomes. On the other hand, if you
attempt to compare the reports from different cultures you are subject to the linguistic translations. Each translation contains traces of an interpretation. In consequence, this means that
experiences which cannot be mediated linguistically in an appropriate way per se, are even more difficult to compare.
With that said the different attempts of categorizing and quantifying a large amount of individual reports should always be considered with a certain kind of reluctance. Such statistics may show instructive guidelines of scientific discussions. Nevertheless, attempts of objectifying subjective experiences are highly problematic from an epistemological and scientific-theoretical viewpoint. This circumstance matches the fact that there are a lot of contrary approaches to define near-death experiences terminologically. Concerning this matter, note the differentiation of terms which is a distinct category on this website. You can find it in the menu bar.
3. Differentiation of varying approaches and explanations: The question of how to interpret or explain near-death experiences scientifically is one of the most controversially discussed questions referring to this topic of research. Below, four categories of approaches or explanations will be differentiated, namely descriptive, religious-ontological, sceptical or reductionist-materialistic and parascientific positions (cf. FN 1). Regardless of the strengths and weaknesses of the following three positions, I want to specify a first approach which can also be helpful for the mediation of different models of explanations, namely a descriptive position striving towards neutrality. Near-death experiences can be considered as phenomena which come up in different religious and linguistic contexts and obviously show parallels to early reports of human culture (this is also admitted by representatives of the so-called sceptical or reductionist-materialistic positions). In this regard, they can be understood as cultural phenomena, which can be discussed on a historical-descriptive level without having to answer the question of adequate or inadequate interpretations straight away. Instead, would you postulate that near-death experiences cannot be the topic of scientific research as a matter of principle, because they evade established scientific paradigms, then this position should be classified as in deficit regarding the theory of science.
Regarding the theory of science, the analysis of near-death experiences has partial affinities to academic theology or the science of religion. The latter can also attend to religious beliefs which are analyzed as cultural reports or expressions of specific world views and conceptions of man without having to discuss the standards of reality of the current conception at the same time or even to understand it as existential (cf. FN 2).
A comparable differentiation of the levels of discussion was often not taken into consideration in
previous scientific discussions regarding near-death experiences. Because of this it is important to initially describe the phenomena, which should be done neutrally. Only then views can be taken
that can be categorized as being religious-ontological, sceptical or reductionist-materialistic or parascientific.
Near-death experiences according to religious-ontological positions are understood as evidence or proof for the existence of an immortal human consciousness respectively an immortal human soul or as proof for the existence of god. Such views were held especially in early seemingly esoteric statements which were partly wilfully, partly unconsciously opposed to scientific approaches. In doing so, subjective experiences are rated higher or as more important than the validation by scientific approaches.
Sceptical respectively reductionist-materialistic approaches can be understood as being the opposite of religious-ontological approaches. Sceptical positions claim that near-death experiences can be explained by means of the established paradigms of the respective sciences (cf. FN 3). For instance, neurophysiologic approaches have tried to interpret near-death experiences as a consequence of brain functional changes. The hypoxia-hypothesis, the temporal lobe-hypothesis or the neurotransmitter-hypothesis can be taken as examples for such explanations. Attempts were made to artificially stimulate different aspects of near-death experiences, e.g. by neurophysiologic mechanisms or pharmacological inductions. The scope of sceptical positions becomes even wider if specific forms of psychological explanations are included in the discussion. In these discourses, it has been variously tried to explain near-death experiences as an unconscious defence mechanism or rather a depersonalization related to life-threatening situations. Near-death experiences were therefore interpreted as specific kinds of hallucinations, illusions, dreams, or intoxication by these neurophysiologic and psychological explanations.
Regarding the history of science, the positions as outlined above are based on assumptions related to a so-called “reductionist materialism” (cf. FN 4). Representatives of these positions act on the assumption that phenomena of different kinds can be traced back to material causes and therefore be explained accordingly. This would be also true for certain aspects of human existence which we call ‘soul’, ‘mind’ or ‘consciousness’. Epistemological main features of such world views and ideas of man have already evolved in pre-Socratic philosophy and have been further developed in different areas of research in the recent history of science. The examination of the premises of a so-called reductionist materialism can be understood as being one of the central questions of the scientific research into near-death experiences and related phenomena. Even if the dimensions of these discourses cannot be described adequately in this context, one central question can be already suggested. A lot of neurophysiologic and psychological statements presuppose a certain under-standing of matter without making it part of the discussion. The key question concerns such under-standings of matter with regard to their historical background. To put it differently: Can the notion of matter as presumed by different reductionist-materialistic world views and ideas of man still be combined with the insights gained by those areas of research which are mainly concerned with the explanation of matter, for instance quantum physics? Profound progress of such discussions is only possible by organizing interdisciplinary groups of research. Scientists of different areas can then continually contribute to the research of near-death experiences (cf. the respective descriptions in the category ‘projects’).
Parascientific positions relate to the descriptive approaches concerning near-death experiences as outlined initially without already evaluating a religious-ontological or skeptical position (cf. FN 5). Parascientific positions are different from sceptical or reductionist-materialistic positions with regard to their understanding of human consciousness and their interpretation of the ‘body-mind problem’. The things which occur during near-death experiences are taken as evidence for the independent existence of consciousness apart from human existence. Therefore, consciousness is not only a product of physiological activities of the brain. Thus, interdisciplinary research could provide new perspectives on the analysis of the ‘body-mind problem’.
It is important to underline that the term ‚parascientific‘ does not have a negative connotation. Moreover, it describes the doubts if a new area of research will prove itself to be a protoscience or pseudoscience (cf. FN 6). Parascientific positions strive toward explaining near-death experiences as phenomena which could not yet be interpreted adequately within the limits of already established scientific paradigms. Rather, they were phenomena which challenge reflections or further developments and maybe even revisions of those paradigms. As long as those approaches are not established in the respective discourses, they can and have to be qualified as parascientific positions. If there will be a shift in paradigms during further discourses, those explanations can be called scientific positions. The primary stages of those discourses can then be labeled retrospectively as protoscience. On the other hand, if they could not establish themselves in the scientific discourse, those approaches would have to be called pseudosciences afterwards.
Regarding the history of science, crucial progress in one area of research was reached by such
paradigm shifts. With that in mind, it is important for the next step to realize which potentials interdisciplinary research into near-death experiences can have.
 This differentiation is partly based on specifications made by D. Vaitl, Veränderte Bewusstseinszustände: Grundlagen – Techniken – Phänomenologie, Stuttgart 2012, 153f. In contrast to those preliminary considerations, the so-called ‚sceptical positions‘ will be called ‚sceptical or reductionist-materialistic positions‘ in order to terminologically denote the often assumed premises concerning the theory of science and epistemology. On the other hand, ‘descriptive positions’ will be treated as a separate group to describe a level of discussion on which all the participants of the other positions must be able to act.
 For instance, the author of this text can be engaged in early Christian beliefs of exorcism as a historical-critical exegete of early Christian reports without having to consult an exorcist when ill. How to cope with those differences concerning the history of civilization, cf. E. E. Popkes, Der Krankenheilungsauftrag Jesu: Studien zu seiner ursprünglichen Gestalt und seiner frühchristlichen Interpretation (Biblisch-Theologische Studien 96), Neukirchen-Vluyn 2014, 140-145.
 Examples for this can be found in O. Blanke/N. Faivre/S. Dieguez, Leaving Body and Life Behind: Out-of-Body and Near-Death Experience, in: S. Laureys/O. Gosseries/G. Tononi: The Neurology of Consciousness: Cognitive Neuroscience and Neuropathology, Amsterdam 20152, 323,347; S. Blackmore, Dying to live: Near-death experiences, New York 1993, passim; J. C. Saavedra-Aguilar/J. S. Gómez-Jeria, A Neurobiological Model for Near-Death Experiences, in: Journal of Near-Death Studies 7 (1989), 205-222; H.-P. Duerr, Die dunkle Seite der Seele: Nahtod-Erfahrungen und Jenseitsreise, Frankfurt a. M. 2015, passim; K. Jansen, Neuroscience and the near-death experience: Roles for the NMDA-PCP receptor, the sigma receptor and the endopsychosins, in: Medical Hypotheses 31 (1990), 25-29; B. Enkmann, Mythos Nahtoderfahrungen, Stuttgart 2011; C. Hoppe, Nahtoderlebnisse – Blick ins Jenseits? in: G. Souvignier (Hrsg.), Durch den Tunnel. Nahtoderfahrungen interdisziplinär betrachtet (Netzwerk-Nahtoderfahrungen/Tagungsberichte 2006), Goch 2006, 89-120; G. M. Woerlee, Mortal Minds. The Biology of Near-death Experiences, Amherst 2005, passim etc.
 For the background of this terminology, especially regarding the history of science, cf. i.a. A. Wittkau-Horgby, Materialismus. Entstehung und Wirkung in den Wissenschaften des 19. Jahrhunderts. Vandenhoeck & Ruprecht, Göttingen 1998, passim.
 For the respective approaches cf. B. Greyson, Near-Death Experiences, in: E. Cardeña/S. J. Lynn/S. Krippner (Hg.), Varieties of Anomalous Experience: examining the scientific evidence, Washington 20074 (erste Auflage 2000), 315f.; W. Kuhn, Rätsel Nahtoderfahrungen: Neurobiologische Erklärungsmodelle und ihre Grenzen, in: R. Lachner/D. Schmelter (Hg.), Nahtoderfahrungen: eine Herausforderung für Theologie und Naturwissenschaft (Vechtaer Beiträge zur Theologie 16), Berlin 2013, 45-62; P. van Lommel, Endloses Bewusstsein: neue medizinische Fakten zur Nahtodforschung, Düsseldorf 20126, passim; P. Fenwick, Gehirn, Geist und was darüber hinausgeht, in: S. Grof u. a. (Hg.), Wir wissen mehr als unser Gehirn, Freiburg i. Br. 2003, 37-56; E. F. Kelly/E. W. Kelly/A. Crabtree/A. Gauld/M. Grosso/B. Greyson, Irreducible Mind: Toward a Psychology for the 21st Century, Lanham u.a. 2007, passim; G. Lier, Das Unsterblichkeitsproblem. Grundannahmen und Voraussetzungen (2 Bände), Göttingen 2010, passim.
 For the definition and establishment of these terms, cf. the articles in the anthologies by G. L. Eberlein (Hg.), Schulwissenschaft, Parawissenschaft, Pseudowissenschaft, Stuttgart 1991; D. Rupnow/V. Lipphardt/J. Thiel, C. Wessely (Hg.), Pseudowissenschaft – Konzeptionen von Nichtwissenschaftlichkeit in der Wissenschaftsgeschichte, Frankfurt a. M. 2008.
4. Interdisciplinary research into ‚near-death experiences‘ and the ‘character of scientific revolutions’: If you are concerned with the history of scientific research into near-death experiences, you get to the question to which extent it embraces something Thomas S. Kuhn, one of the most high-profile philosophers of science and historians of science of the 20th century, called the ‘character of scientific revolutions’ (cf. FN 1). The highly controversial debates give rise to one theoretical and epistemological key question over and over again. The question is: can near-death experiences be explained sufficiently within the framework of established paradigms of the sciences involved in the discussion, or do they rather challenge revisions or enhancements of those paradigms? It is important to keep in mind that Thomas S. Kuhn could demonstrate on the basis of different areas of research that such paradigm shifts do often not occur because of continuous developments in one discourse. This was especially the case if the scientists involved were not able to self-critically challenge the paradigms of their discipline that have evolved over many years and redetermine them where necessary.
Furthermore, there is no consensus in those areas of research that formulate the sceptical or reductionist-materialistic positions as outlined. For instance, different neurophysiologists and psychologists refuse to accept near-death experiences as being hallucinations, dreams after drug usage or emergency functions of a dying brain because of scientific observations. A key question of those discourses can be expressed by a statement of a participant of the discourse, who is predestined because of his scientific qualifications. The neurologist and psychologist Dieter Vaitl has formulated a summary in a more recent study concerning near-death experiences, which puts the dilemma of scientific discussions nowadays in a nutshell:
„Die erste und zentrale Frage lautet: Wie können mentale Prozesse bei klarem Bewusstsein ablaufen, wie sie von NTE-Betroffenen geschildert werden, wenn die bisher bekannten neurophysiologischen und zerebralen Prozesse für einen Bewusstseinsverlust sprechen? (...) Beim derzeitigen Kenntnisstand müssen wir uns eingestehen, dass es für die oben geschilderte Diskrepanz keine plausible Erklärung gibt. Es ist und bleibt ein Paradox!“ (cf. FN 2)
"The first and central question is: How can mental processes occur meanwhile clear consciousness, how they are described by near-death-experiencers, when the common processes within in the field of neurophysiology and cerebral processes indicate a lack of consciousness? (…) Meanwhile the current state of knowledge we of to admit that there is no explanation for this discrepancy. Currently this is a paradoxic phenomenon." (Translation by Enno Edzard Popkes).
This paradox as stated by Dieter Vaitl is even more remarkable if you take into consideration which key questions still shape the scientific discourses. There are plenty of unanswered questions, but I want to name only some significant examples: For instance, how is it possible that human beings who have been blind since their early childhood or were even born blind can describe how they looked like during a near-death experience and where the life-threatening happenings took place? How do you explain that deaf people can give an account of the conversations the rescue workers had while rescuing those people from mortal danger? How does it come that people can describe in detail what happened during an operation they had while they were under general anesthesia, the specific measures taken by the doctors and what else happened even outside the OR? Why do people almost exclusively meet deceased during near-death experiences? And how can we explain that they know about deceased family members of whose existence they have not heard before? How can we explain that many people have massive psychological problems after hallucinations or intoxications after drug usage whereas most people who had a near-death experience take this experience in itself as the foundation of a new, positive world view? How does it come that many people experienced medical healing as a consequence, a healing without explanation in the categories of conventional medicine? And if – as has been postulated on various occasions – all parts of near-death experiences could be artificially produced by neurophysiologic mechanisms or pharmacological inductions, then why can their therapeutic potentials not be artificially caused on psychological and physiological levels? Why are the key aspects of ‘near-death experiences in the narrower sense’ so alike, even though they can be from totally different cultural contexts? Do you want to claim that every human being has a comparable neuronal program which will make the own death easier for him or her? And if this should be the case, how do you make sense of terrible happenings close to death which do not exactly make the process of dying easier?
Research into near-death experiences is concerned with those questions since the beginning, and will continue with them. They illustrate the actual key questions of scientific discourses regarding near-death experiences. Near-death experiences are theoretical border cases that can offer new perspectives on a central question of human existence: what is ‘consciousness’? How can we describe the relationship between what we call ‘mind’, ‘soul’, and ‘body’? How do ‘mind’ and ‘matter’ relate? Former discourses often use redundant repetitions of comparable statements and structures in the discussions. Profound progress of such discussions is only possible by organizing interdisciplinary groups of research. Scientists of different areas can then continually contribute to the research of near-death experiences. To strengthen the interdisciplinary research is one of the central aims of those projects run at the University of Kiel in the future.