Definitions for "Phenomenalism"
Phenomena is that which appears. The phenomenalist says that substance and causality are no more than bundles of perception. Therefore there is no rational knowledge beyond what is disclosed by the phenomena of perceptions. Mind is no more than a bundle of perceptions.
The doctrine that the appearances of things are their reality; there are no things in themselves, but only things in relation to our experience.
In epistemology and the philosophy of perception, phenomenalism is the view that physical objects do not exist as things in themselves but only as perceptual phenomena or sensory stimuli (e.g. 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.
The idea that only observable phenomena should be studied. Positivism
That theory which limits positive or scientific knowledge to phenomena only, whether material or spiritual.