Rare phenomena, such as near-death and past-life experiences, alien abduction, telepathy and clairvoyance, steadily become the object of scientific investigation. Varieties of Anomalous Experience brings about persuasive evidence that science in general, and psychology in particular, can tell us a lot about such phenomena, which, as estimated, are experienced by a substantial part of the general population. The authors, however, carefully delineate the questions which lie beyond the competence of science, while they do not hesitate to point out the prejudices common in scientific practice and our ordinary life which are ungrounded by the scientific evidence.

The volume edited by Cardeña, Lynn, and Krippner is co-authored by 21 world-known experts in investigating anomalous experiences. The first part (chapters 1 and 2) discusses the choice of appropriate concepts, variables, and research methods to study anomalous experiences. A major concern is on how to conduct and assess reliability of self-reports, which in the prevailing part of anomalous experiences constitute the main source of the available data. The second part (chapters 3 through 12) examines a comprehensive list of anomalous experiences: hallucinations, synesthesia (e.g. visual or gustatory perception of sounds), lucid dreaming (awareness while dreaming), out-of-body experiences, psi-related experiences (e.g. telepathy or clairvoyance), alien (esp. UFO) abduction experiences, past-life experiences, near-death experiences, anomalous healing, and mystical experiences. The second edition of the book, I hope, will also contain a third part on comparative studies correlating different kinds of anomalous experiences.

What proves extremely helpful in reading the second part is the common structure of the papers: a case study, which is used to elaborate a relevant definition, the discussion of the parts and forms of the experience, the individual differences, aftereffects, a survey of available results, hypotheses and theories, the discussion of applicability and reliability of different methods, and conclusions for future research.

The book impressed me as a self-contained companion to scientific, mainly psychological, research on phenomena which "deviate from ordinary experience or from the usually accepted explanations of reality". Although this is neither a textbook nor a self-guide, it will surely be of interest to a very wide audience. For it is one of the most systematic attempts so far to scientifically evaluate rare phenomena experienced by, as the authors contend, the majority of the general population.

Its clear and readable style makes it accessible to the general public. A number of concrete illustrations and citations from self-reports of the experients makes up for more demanding parts of the text. In addition, the authors seek to clearly define all key terms, and give an explanation of most of technical terms. Nevertheless, to avoid repetition and confusion, it would be better to have a glossary of all the terms together with acronyms. I must also add that only the last chapter contained extensive footnotes, which are printed in annoyingly small font.

The book may well serve to set the agenda for the future research on anomalous experiences. The definitions of the experiences and the choice of research methods are carefully examined and well motivated in all contributions. The critical, and in most cases penetrating, survey of the available research results is accompanied by an extensive list of references, which sum up to 100 pages overall.

Besides the general public, psychologists, philosophers, and scientists, the book is also addressed to psychiatrists, therapists, and clinicians. Every chapter in the second part of the book contains a section on diagnosis of each anomalous experience as opposed to pathologies as well as on therapy of the experients.

The recurrent message of the contributions is that scientific evidence definitely rejects the view that anomalous experiences are pathological. On the contrary, they constitute a part of the "continuum" of ordinary experience. Therefore, the study of anomalous experiences shall not "be conducted solely in the context of a psychology of the exotic or the unusual, but in the wider context of the study of the totality of human experience". The rationale is, as I conjecture from casual remarks, the evolutionary approach announced in the introduction. Anomalous experiences constitute a normal variation within the broader scope of human experiences, which have to be studied in the view of their adaptive role.

The authors are right to emphasize the positive role of this approach: anomalous experiences are no longer considered as pathologies grounded in physiological or psychological impairment. Moreover, the impressive amount of accumulated evidence reveals that if there is any correlation between anomalous experiences and mental health, it is rather positive. The aftereffects of many of the anomalous experiences, especially of near-to-death experiences, synesthesia and lucid dreaming, have already demonstrated positive therapeutic results.

This approach is not necessarily in conflict with the hypothesis that anomalous experiences give us access to a non-empirical reality, which is not accessible to ordinary experience. In practice, however, most of the authors proceed with a more or less explicit working hypothesis that the "validity" of the experience is only projected or constructed by the experient. And the proposed models or theories are often intended to explain away this validity. Only once in this lengthy volume the question is raised whether the physiological and psychological model explaining a given anomalous experience, totally generates this experience or results from experiencing a reality which is not susceptible to ordinary experience. And nowhere in the book an empirical study is cited to support the view that a genuine anomalous experience is generated without the presence of an object of the experience.

This issue, however, should find its place in the first part of the book. Otherwise, it is ambiguous what precisely is under scrutiny: the psychological experience and/or accompanying physiological, physical, chemical phenomena or even non-empirical phenomena. This ambiguity most seriously undermines the integrity of the book. Some authors seek to provide empirical evidence for or against anomalous experiences. For instance, lucid dreaming, which implies that the experient controls the behavior while dreaming, is proved by the record of eye movements during a dream, which match precisely the prior arrangement. Near-to-death experiences are proved real by the veridical report of events by an experient, whose brain functioning was recorded to stop. Other authors, however, concentrate exclusively on the psychological part of the experience. For instance, healing experiences are investigated in isolation from healing events. The problem, however, of empirical verification of the theories of healing experiences is not even raised, and this is the reason why I find the lengthy chapter on anomalous healing one of the least informative in the book. Similar considerations concern chapters on psi-related and mystical experiences.

There are lots of central questions that, as the editors declare, are not answered in the book: Which, if any, of the anomalous experiences reliably indicate a non-empirical reality? Do the experients constitute a special category of people? How shall I define and evaluate my own rare experiences? Is there anything pathological in my rare experiences?

The volume brings together immense amount of studies, which give us cutting-edge perspective on scientific research on anomalous experiences. On the one hand, it becomes perspicuous that many aspects of the experiences are susceptible to scientific investigation. On the other hand, however, it makes us aware that the science of the anomalous is far from complete. Hopefully, the future research will profit from closing the gap between the scientific study, and the centuries-old traditions of investigation of anomalous experiences, such as yoga or mysticism.

Categories: General, Philosophical