The distinction between phenomenalistic perception and rational understanding of the world is one of the classic distinctions in philosophy and psychology. Rational understanding is usually viewed as being based on scientifically accepted theories, methods of analysis, measurement, and interpretation of experience. This type of understanding may differ substantially from the phenomenalistic perception of the same events and objects, that is, not mediated by scientific conceptions and theories. Attempts to reduce the distressing diversity of the phenomenal world to a limited number of mental constructions (e.g., “primary substances,” numbers or atoms) can be traced back to antiquity (Sextus Empiricus, 1933), yet such attempts became particularly persistent in recent centuries. With the development of scientific knowledge and a rational means of analysis and explaining experience, rational interpretation began to be viewed as the “essential” and true interpretation, while phenomenalistic perception acquired the status of something that is not real but only apparent and illusory.

Descartes, referring to the relation between phenomenalistic and rationalistic descriptions of sound, wrote: “Most philosophers believe that sound is only a vibration of the air impinging on our ears; thus, if our sense of hearing conveyed to our thought a true image of its object, instead of giving us the ability to perceive sound, this would compel us to perceive the movements of the particles of air that at the time happen to be vibrating near our ears” (Descartes, 1957, p. 174).