All the perception we have of what surrounds us comes from our (very limited) senses. We cannot think out of the box (brain), because all we 'think' is made up by it, and our senses.
We think there are dimensions, but the whole concept of "dimensions" derives from our hard-wired perception, and way of thinking.
"...
putting Descartes before the horse"
I see what you did there. So there are several ones? Poor horse
