The following text is my 500 word response to the above essay question for the course Introduction to Neuroeconomics: How the Brain Makes Decisions on Cousera.
‘Cogito, Ergo Sum’ wrote René Descartes — ‘I think, therefore I am’. His rationalist argument was that the only we could trust was our conscious thoughts — our “inner-voice”. He argued our senses could be deceiving us, positing that we cannot know a demon is not deceiving us with false inputs — as in the “The Matrix”. His refutation of empiricism is a central text in the historical belief of dualism — i.e. that the human mind is separate from the body; that we are the “Ghost in the Machine”. 
Subsequent research has advanced our understanding of ourselves beyond the ancient guesses about the nature of thought. The physicalist paradigm assumes that all that exist is built upon the physical world and its interactions.  This paradigm assumes that human consciousness is a manifestation of processes running in our physical bodies, on the nervous system and under the influence of our endocrine system.  The physicalists accept emergence as an ontological reality and that our consciousness emerges out of the interactions between our neurons.