was first proposed by William K. Clifford, a British mathematician which implied that a single substance of reality is in fact a combination internally of the mind but appears externally as the form of matter which we observe in day to life.

MIND STUFF: "The concept of reality, whilst debated, was proposed by William K. Clifford, as being an internal construct of our brain chemistry but actually appears externally as what we see."
Cite this page: N., Pam M.S., "MIND STUFF," in PsychologyDictionary.org, April 7, 2013, https://psychologydictionary.org/mind-stuff/ (accessed May 15, 2021).