It's a basic philosophical problem.
Nothing can transcend its own nature.
No matter how smart you are, you can't write a computer program that can come out of the computer and be "real" with everything else out here in the real world.
No matter how badly you're losing in a Monopoly game, any riches/debt is sandboxed in the "game world". You won't find your real-world checking account affected (for good or ill) from the outcome of a Monopoly game -- not if you tried for 1 trillion years.
Likewise, something 100% physical can't transcend the physical world, or have an INTELLECT. Intus legere is to "read within" or to be able to perceive the essence of individual things. Goodness, evil, justice, chair-ness, etc.
Pretty much ANYTHING abstract is in this category -- including language. Each word is an abstraction, or concept, of something that exists in the real world.
Humans have this wonderful "intellect" which made them the kings of the physical world, because we are hybrid creatures having an IMMATERIAL soul. That is why we can wrap our minds around, and completely understand even the essence of, material things. No animals can do this.
The angels are even more powerful, because they don't have a meat-brain to get in the way of complete intellection. Angels don't even reason (which is slow and plodding, and requires a meat-brain and expending of glucose), because their intellect is more advanced.
And guess where our Reason and Free Will come from? Our soul. Our passions come from our body -- and that is what we share with the brute beasts: anger, happiness, fear, pleasure, etc.