In epistemology and the philosophy of perception, phenomenalism's the view that physical objects don't exist as things in themselves but only as perceptual phenomena or sensory stimuli (for example redness, hardness, softness, sweetness, etc.) situated in time and in space. In particular, phenomenalism reduces talk about physical objects in the external world to talk about bundles of sense-data. Historical overview Phenomenalism's a radical form of empiricism and, hence, its roots as an ontologi… (More on Phenomenalist)