The Word is: Physicalism
In a recent article from Seed, David Weisman debunks the idea of a unified mind, and in so doing also debunks the idea of a unified soul.
I was struck by the following quote in which he expresses regret at the lack of a word for capturing the idea that the mind is entirely physical:
I wish there were a term in the English language that honestly captures the idea that all we experience is due to brain function. ”Materialism” comes close, but is laden with excess metaphysical baggage. The philosopher John Searle coined “biological naturalism” as a mind-body theory within philosophy, and that comes very close. “Asoulism” is more modest: a simple disbelief in the existence of souls based on evidence.
Well David, I have good news for you! There is such a word! And it inspired my second "The Word is:" post:
The word is: Physicalism
Physicalism is, in a nutshell, the idea that everything that exists is ultimately physical, including things that don't typically fit into naive interpretations of the word 'materialism'. The category of 'physical' includes the category of 'material', but also includes things like space, time, forces, and crucially, information and processes. The category 'physical' is also included within the larger category of 'natural'. If it can be detected by the physical sciences, it's physical.
Essentially, the mind is a physical information process, not a non-physical mysterious entity like a 'soul'. The mind can be studied and understood through purely scientific investigations, and in principle -- if not yet in practice -- we could eventually develop sufficient knowledge of the mind to construct a synthetic replica of a true mind, much like Craig Venter has made the first steps toward constructing a synthetic replica of true life.
The word 'physicalism' is more than just a re-packaging of scientific materialism. It provides a nearly unassailable foundation for skeptical, rational, evidence-based arguments and counter-arguments with supernaturalists, including those who Weisman in the above Seed article dubs 'soulists'.
I highly recommend using 'physicalism' in place of other less-clear and less-specific words such as: materialism, naturalism, 'bright', functionalism, reductionism, scientism, pantheism (or panpsychism), holism, etc. Several of these words are loaded with baggage that can derail a discussion and leave you arguing in circles. Just tell 'em, "I'm not a materialist, I'm a physicalist."
A while back, I made a decent video explaining the usefulness of the word 'physicalism':