According to James Edward Beichler , editor of YGGDRASIL: The Journal of Paraphysics , what paraphysics is "has never been precisely defined". The word "paraphysics" itself, according to Beichler (citing Mitchell ), appears to have been coined by German psychiatrist and psychical researcher Baron Albert F. von Schrenck-Notzing in the late 19th century. However, unlike the concept of parapsychology, which has been widely acknowledged (although not necessarily respected) as a field and "can be found in any standard dictionary or encyclopedia" , the concept of paraphysics has not had proponents of the stature of people such as Joseph B. Rhine to pioneer it and has thus not garnered similar acknowledgement. The concept of paraphysics has indeed, again according to Beichler , been mis-used by the pop-culture of "occult phenomena", coöpting the name, resulting in what paraphysics actually is being ambiguous and not clearly defined, with many of the physicists who work in the field of paraphysics being widely regarded as working in the field of parapsychology.
Paraphysics is the domain of paraphysicists. Martin Gardner defines a paraphysicist as "a physicist who investigates the paranormal".  The Society for Psychical Research defines a paraphysicist as a researcher into paranormal physical phenomena who has "the skills of an engineer or a physicist" (as opposed to a parapsychologist who researches extra-sensory perception as a branch of experimental psychology), although it argues that in fact psychical research involves skills from many disciplines.  Beichler derives two summaries of what the concept of paraphysics is.  From the Oxford English Dictionary's definition of "paraphysical" and "parascience" he extrapolates the summary that paraphysics is "the study of physical phenomena which seem to be beyond the scope of ordinary physics, or for which no apparent physical explanation can be found". The other he takes from Bletzer: 
Paraphysics — the study of PHYSICS in relationship to psychic phenomena;
- Study of: (a) physics of paranormal processes; activity that resembles physical phenomena but is without recognizable physical cause; (b) (B. Herbert); anomalous physical effects not explained by current physical theories;
- (Laboratory) an approach to PSYCHIC ENERGY above and beyond the usual study of physics;
- Investigations made on the borderline of both physics and psychic phenomena. Syn. PARAPSYCHOLOGY.
Beichler criticizes Bletzer, in that her definition of paraphysics contradicts her definition of "paraphysical". Beichler argues that the latter is simply the adjectival form of the former, and that therefore the two definitions must have "an intimate and total correspondence". Beichler also criticizes Bletzer's definition of paraphysics as being problematic for its acknowledgement as a legitimate field because of the dedication of Bletzer's work to "New Age" religions and philosophies rather than a strict scientific discipline.  Beichler states that renewed interest in paraphysics arose in the 1970s, with the mainstream acknowledgement of the field of parapsychology engendering renewed interest in paraphysics. He points to essays on "The Emergence of Paraphysics" by James B. Beal and Brendan O'Regan, and Mitchell describing the "emergence of paraphysics as a science". Mitchell's own definition of the concept of paraphysics is that it is "a new field within noetics that is extending the laws and methods of physics in an attempt to explain some paranormal phenomena".  Beichler also gives a definition of the concept of paraphysics from Musés :"paraphysics [denotes] the field of phenomena covering interactions of nonphysical things (such as consciousness) with physical bodies and objects."
Angoff  writing in the 1970s gives a more general definition of paraphysics as being akin to parapsychology but "with the accent on physics rather than upon psychology", and thus being "the study of anomalous physical events". However, the renewed interest in paraphysics faded in the 1980s, in part, Beichler states, because of the failure of parapsychology to produce the hoped-for results. As the Society for Psychical Research puts it, "the yield in terms of testable scientific hypotheses, or of dependable effects of sufficient magnitude, consistency, and reproducibility to permit advances in understanding, has been disappointingly small." 
Bonewits and Emmons , writing in the 1980s, define the field of paraphysics as "the study of (a) the overlaps between parapsychology and physics and (b) the study of the various forms of psychokinesis". Beichler, writing in the 1990s about what he expects to be the "birth of paraphysics as a legitimate science", presents an argument that there is an expectation by several physicists of a paradigm shift in physics in the (relatively) near future, and that some physicists are defining the concept of paraphysics as being what they predict physics will be like after that shift. Beichler quotes Stenger  as writing "If physics is the study of the nature of matter, then we might term the study of a world beyond matter paraphysics." and characterizes this new concept of paraphysics as "the physics of other worlds".
Stenger himself writes  that physics is "misused and misinterpreted in support of a wide range of paranormal and paranatural claims", decrying what he states to be the mis-use of the words "energy" and "quantum" to suggest a scientific basis for "energy therapies" and mind-over-matter healing, the misinterpretation of quantum mechanics to imply that psychic phenomena such as extrasensory perception are real, and the employment of the strong anthropic principle as evidence for intelligent design.
Beichler's own definition of paraphysics is thus that it is a "branch of physics" that is "the logical study of paranormal phenomena within the normal context of physics", or, more broadly, the "logical study of those phenomena occurring in nature which cannot be understood within the context of either matter in motion or our normal concepts of space and time" incorporating the "physics of other worlds." 
- James Edward Beichler (May 2000). "The paraphysical principles of natural philosophy". DAI-B 60 (11): 5561. http://adsabs.harvard.edu/abs/1999PhDT........52B.
- Edgar D. Mitchell (1974). John White. ed. Psychic Exploration: A Challenge for Science. New York: Putnam's Sons. pp. 25–26,486. ISBN 978-0399113428.
- James E. Beichler (1996). "THE NEW AND IMPROVED PARAPHYSICS". YGGDRASIL: The Journal of Paraphysics. http://members.aol.com/jebco1st/Paraphysics/pphysics.htm.
- Martin Gardner (May/June 1977). "Geller, Gulls and Nitinol". Humanist. http://www.zem.demon.co.uk/gardner.htm.
- "A Career in Parapsychology". Society for Psychical Research. http://www.spr.ac.uk/index.php3?page=career.
- June D. Bletzer (1986). The Donning International Encyclopedic Psychic Dictionary. Norfolk: The Donning Company. ISBN 089865372X.
- Charles Musés (1977). "Paraphysics: A New View of Ourselves and the Cosmos". in John White and Stanley Krippner. Future Science: Life Energies and the Physics of Paranormal Phenomena. Garden City, NY: Anchor Press. pp. 280–288.
- Allan Angoff (1971-06-01). Century of Psychical Research: The Continuing Doubts and Affirmations. Proceedings of an. Parapsychology Foundation. pp. 145. ISBN 0912328193.
- Isaac Bonewits and Philip Emmons (1989-10-01). Real Magic: An Introductory Treatise on the Basic Principles of Yellow Magic. Weiser. pp. 212. ISBN 0877286884.
- Victor J. Stenger (May 1990). Physics and Psychics: The search for a world beyond the senses. New York: Prometheus Books. pp. 8. ISBN 087975575X.
- Stenger, Victor J. (2000-03-24). "Paraphysics: Physics Misused and Misinterpreted". American Physical Society, Annual March Meeting, March 20-24, 2000 Minneapolis, MN.
- James E. Beichler (1996). "PHYSICS AND PARAPHYSICS". YGGDRASIL: The Journal of Paraphysics 1 (1). http://members.aol.com/jebco1st/Paraphysics/issue1.htm.
- Jeffrey Mishlove. "4.1: Theory of Consciousness: The Biological Perspective". The Roots of Consciousness. http://www.williamjames.com/Theory/BIOLOGY.htm.
- Note 1: Another Journal of Paraphysics was published by Benson Herbert in England in the 1960s and 1970s.
- Jon. Klimo (1998-04-01). "Biology and Physics". Channeling: Investigations on Receiving Information from Paranormal Sources. North Atlantic Books. pp. 306–364. ISBN 1556432488. — Klimo writes on "physics and paraphysics"
- James E. Beichler (Spring 2001). "To Be or Not to Be! A "Paraphysics" for the New Millennium" (PDF). Journal of Scientific Exploration (Society for Scientific Exploration) 15 (1). http://www.scientificexploration.org/jse/articles/pdf/15.1_beichler.pdf.