Identification
Not always is it a mistake to treat different things (from different spaces) as if they were one and the same. Actually, it is often quite natural and inevitable. So, for example, when a physical object is identified by — and with! — its name or symbol. Without such an identity it would be impossible to speak about anything, to comprehend anything, to know anything.
What we do in cases like that is creating — or using — a new thing comprising the others, which by themselves remain what they are: distinct, actually incompatible. But their spaces can penetrate one another. So they can form a new space for the new thing, which is different from the original things, although somehow combining them.
This process is extremely important, it is fundamental for knowledge of any kind. We have called it the central “act of knowing”. It is the process by which we get a mental representation of the physical thing, in combining it with the proper symbol, so to speak.