It is incorrect to say that mind, emotion, and soul are merely a physical phenomenon, merely the sum of physiological and physical processes.  This is not incorrect because mind, emotion, and soul are more than the physical, but rather because the physical is never “mere.”

Is a $100 bill merely a piece of paper?  Of course not.  It is a piece of paper with meaning, and there is a universe in that meaning.  The meaning is astronomically more important than the paper.  But where does that meaning exist?  Does a $100 bill have a soul?  Is there some spiritual essence of the $100 bill existing in some higher dimension, encompassing all of that meaning, anchored to the physical object like a ghost anchored to its corporeal chassis?  Plato would probably say there is, and perhaps there is, or perhaps that’s a way to think about it, but for any practical purpose the information is there in the paper, and in the very specific arrangement of pigment molecules amongst its fibers, an arrangement which could never arise by random process and which conveys to an intelligent, educated mind the bill’s significance.  You can imagine some Platonic virtue of the $100 bill if you like, but without a piece of paper so marked, there would be no $100 bill before you.  Therefore, you cannot say it is merely paper and ink—not and be speaking intelligently.  You must say that it is a piece of inked paper so configured as to represent profound information.  It is paper and ink and a miracle.

Would you say Beethoven’s symphonies are merely arrangements of tones?  Would you say Shakespeare’s plays are merely sequences of words?  Only if you were profoundly stupid and arrogant at the same time.  You would as well say, “Oh, I’m merely looking into the aperture at the end of a metal tube,” when staring into the muzzle of a gun.  The meaning is the only thing that means anything.

Likewise, your feelings are for any practical purpose, flesh, the sum of your physiological reactions to a stimulus.  But merely that?  To say they are “merely” that is to improperly discount the astronomical complexity of information that particular arrangement of physiological processes contains and conveys.  Are your mental processes merely patterns of electrical discharge across the brain?  No, they are patterns of electrical discharge across the brain with meaning, and to add “with meaning” is to explode that statement from a trivial observation to a declaration with all the grandeur of a cosmos.

So, when someone attributes something which you think of as spiritual to the “merely physical,” before you get bent out of shape about whether or not the spiritual dimension exists, please take to task your counterpart for discounting the most important dimension of anything physical: its information content.  It is the meaning that is the most important part of anything which has meaning.