Dept. Of Philosophy Name of the teacher:-Achintya Ghosh History of Phenomenalism The roots of Phenomenalism as an ontological view of the nature of existence can be traced back to George Berkeley and his Subjective Idealism, which David Hume then further elaborated. Berkeley's beliefs were an early kind of bundle theory (the idea that objects are made up of sets, or bundles, of ideas or perceptions), and that when the characteristics of an object are no longer being perceived or experienced by anyone, then the object effectively no longer exists (although Berkeley argued that God always perceived everything, thus maintaining the existence of objects which were not subject to observation by humans). The 19th Century empiricist John Stuart Mill developed the first phenomenalist theory of perception (commonly referred to as Classical Phenomenalism), which did not require the intervention of God. He spoke of physical objects as the "permanent possibility of experience". As a robust epistemological theory, however, Phenomenalism can be traced to the Transcendental Idealism of Immanuel Kant. He insisted that knowledge is limited to phenomena, although he never denied or excluded the existence of objects which were not knowable by way of experience (the "things-in-themselves" or noumena), even if they were not provable. In the late 19th Century, an even more extreme form of Phenomenalism was formulated by the Bohemian-Austrian philosopher Ernst Mach , and later developed and refined by Bertrand Russell, A. J Ayer and the Logical Positivism movement. Sensory phenomena, for Mach, are "pure data" with no need of being experienced by the mind or consciousness of subjects. The logical positivists went on to formulate the doctrine of Phenomenalism in linguistic terms. Sem- IV Paper- CC-10 ( Epistemology and Metaphysics) .