We begin by discussing ``What exists?'', i.e. ontology, in Classical Physics which provided a description of physical phenomena at the macroscopic level. The microworld however necessitates a introduction of Quantum ideas for its understanding. It is almost certain that the world is quantum mechanical at both microscopic as well as at macroscopic level. The problem of ontology of a Quantum world is a difficult one. It also depends on which interpretation is used. We first discuss some interpretations in which Quantum Mechanics does not provide a complete framework but has to be supplemented by extra ingredients e.g. (i) Copenhagen group of interpretations associated with the names of Niels Bohr, Heisenberg, von-Neumann, and (ii) de-Broglie-Bohm interpretations. We then look at some interpretations in which Quantum mechanics is supposed to provide the entire framework such as (i) Everett-deWitt many world, (ii) quantum histories interpretations. We conclude with some remarks on the rigidity of the formalism of quantum mechanics, which is sharp contrast to it's ontological fluidity.
Quantum theory is open to different interpretations, and this paper reviews some of the points of contention. The standard interpretation of quantum physics assumes that the quantum world is characterized by absolute indeterminism and that quantum systems exist objectively only when they are being measured or observed. David Bohm's ontological interpretation of quantum theory rejects both these assumptions. Bohm's theory that quantum events are party determined by subtler forces operating at deeper levels of reality ties in with John Eccles ' theory that our minds exist outside the material world and interact with our brains at the quantum level. Paranormal phenomena indicate that our minds can communicate with other minds and affect distant physical systems by nonordinary means. Whether such phenomena can be adequately explained in terms of nonlocality and the quantum vacuum or whether they involve superphysical forces and states of matter as yet unknown to science is still an open question, and one which merits further experimental study.
The usual interpretation of the quantum theory is self-consistent, but it involves an assumption that cannot be tested experimentally, viz., that the most complete possible specification of an individual system is in terms of a wave function that determines only probable results of actual measurement processes. The term ‘ontological interpretation’ is sometimes applied to Bohm’s approach, as he set out to tackle the ontological problems of conventional quantum theory. However, the ontological interpretations are strikingly different. In the many worlds view, the differing branches are simultaneously and equally real, whereas Bohm’s inactive channels remain as unmanifested potentialities, with steadily declining likelihoods as more and more irreversible process (like measurement) pile up along the manifest branch. Bohm’s theory serves to illuminate some of the more interesting aspects of quantum theory (its contextuality and nonlocal nature) and demonstrates what is at stake from an ontological point of view.
Quantum mechanics is often perceived as conceptually paradoxical because it appears to conflict with deeply rooted intuitions about fixed reality, determinism, and observation. This paper does not propose a new physical theory. Instead, it offers an epistemological reframing of quantum mechanics: not as a direct mathematical unveiling of a fully fixed pre-existing reality, but as a highly precise description of phenomenological structures emerging through observational conditions and interaction. The paper explores: the distinction between mathematical predictive success and ontological completeness, the role of human perception in constructing “fixed reality” intuitions, the phenomenological nature of qualities such as color and temperature, the possibility that some conceptual tensions in quantum mechanics arise from assumptions inherited from macroscopic cognition, and how quantum theory may be interpreted as describing observable structures rather than fixed hidden states. The work intentionally avoids mystical, anti-scientific, or consciousness-centric interpretations of quantum mechanics. It does not deny the existence of reality, nor reject modern physics. Rather, it attempts to clarify what exactly mathematical models are describing when applied to quantum phenomena. This text is positioned as a conceptual and phenomenological reorganization of perspective — a small doorway toward reconsidering how humans frame “reality” itself.
Quantum physics, in contrast to classical physics, allows non-locality and indeterminism in nature. Moreover, the role of the observer seems indispensable in quantum physics. In fact, quantum physics, unlike classical physics, suggests a metaphysics that is not physicalism (which is today’s official metaphysical doctrine). As is well known, physicalism implies a reductive position in the philosophy of mind, specifically in its two core areas, the philosophy of consciousness and the philosophy of action. Quantum physics, in contrast, is compatible with psychological non-reductionism, and actually seems to support it. The essays in this book explore, from various points of view, the possibilities of basing a non-reductive philosophy of mind on quantum physics. In doing so, they not only engage with the ontological and epistemological aspects of the question but also with the neurophysiological ones.
According to the Everett interpretation of quantum mechanics, the apparent paradoxes of quantum theory require no change either in our philosophical attitude toward scientific theories or in the formalism of quantum mechanics itself. Rather, the unaltered theory can be understood as a literal description of physical reality. But the physical reality thus described is one of many noninteracting, approximately classical worlds. These worlds enter the theory not at the fundamental level—they are nowhere to be found in the basic formalism—but at a higher, emergent level; in this sense they are (ontologically speaking) on a par with the ontology of the special sciences.