To me this song means that the deception of the mind through natural emotions passed through our natural ancestors can create a situation in which you believe you saw or felt something that truly doesn't exist while your mind tells lies and justifications. Those deceptions could be ghosts, angels, god, monsters, whatever the mind can conjure. The main idea is that you should learn to give up on something that isn't actually there and overcome what the mind is telling you even if it is painful.
To me this song means that the deception of the mind through natural emotions passed through our natural ancestors can create a situation in which you believe you saw or felt something that truly doesn't exist while your mind tells lies and justifications. Those deceptions could be ghosts, angels, god, monsters, whatever the mind can conjure. The main idea is that you should learn to give up on something that isn't actually there and overcome what the mind is telling you even if it is painful.