A physical system showing a classical (deterministic) behavior to an observer can appear to be a quantum system to another observer unable to distinguish between some distinct states.
Philosophical discourse traditionally distinguishes between ontology and epistemology and generally enforces this distinction by keeping the two subject areas separated. However, the relationship between the two areas is of central importance to physics and philosophy of physics. For instance, many measurement-related problems force us to consider both our knowledge of the states and observables of a system (epistemic perspective) and its states and observables independent of such knowledge (ontic perspective). This applies to quantum systems in particular. This contribution presents an example showing the importance of distinguishing between ontic and epistemic levels of description even for classical systems. Corresponding conceptions of ontic and epistemic states and their evolution are introduced and discussed with respect to aspects of stability and information flow. These aspects show why the ontic/epistemic distinction is particularly important for systems exhibiting deterministic chaos. Moreover, this distinction provides some understanding of the relationships between determinism, causation, predictability, randomness, and stochasticity.
Quantum physics provides a good candidate for a mathematical entity, namely, the quantum state vector in the Hilbert space. The causal potency problem originates from determinism: In classical physical theories there are fundamental constituents entering in the mathematical description of the physical laws that govern deterministically the dynamics of physical systems. Since only these fundamental constituents are causally potent to affect the deterministic behavior of physical systems, consciousness has to appear as a fundamental constituent of the physical theory as well. Existentialism clashes seriously with determinism. Classical deterministic physics allows no free will and no objective morality. Classically, functionalism leads to epiphenomenalism because the generated conscious experiences are unable to change the already predetermined future dynamics of the brain. In quantum physics, however, the quantum indeterminism in the dynamics of quantum systems provides a multitude of possible outcomes from the measurement process.
Abstract. Traditional philosophical discourse draws a distinction between ontology and epistemology and generally enforces this distinction by keeping the two subject areas separated and unrelated. In addition, the relationship between the two areas is of central importance to physics and philosophy of physics. For instance, all kinds of measurement-related problems force us to consider both our knowledge of the states and observables of a system (epistemic perspective) and its states and observables independent of such knowledge (ontic perspective). This applies to quantum systems in particular. In this contribution we present an example which shows the importance of distinguishing between ontic and epistemic levels of description even for classical systems. Corresponding conceptions of ontic and epistemic states and their evolution will be introduced and discussed with respect to aspects of stability and information ow. These aspects show whytheontic/epistemic distinction is particularly important for systems exhibiting deterministic chaos. Moreover, this distinction provides some understanding of the relationships between determinism, causation, predictability, randomness, and stochasticity inchaotic systems.