InterDimesional

My twin brother and I actively research and discuss theories involving dimensions, alternate universes, etc, and we have recently gotten into a debate in which we have more problems than usual when it comes to him convincing me and vice versa. Our discussions are usually not more than a few hours long, but this has been going on for days! The argument is about how beings of a certain dimension perceive themselves. I believe that beings of any dimension can not perceive their own dimension, but can only see things in dimensions lower than they are. I argue that, if first dimensional beings would only be lines, they would only be able to perceive points (virtually representing a "zero" dimension, as no true measurements would exist in such a place), that two dimensional beings, despite being shapes, would only see lines and points (length only, first dimension), and that three dimensional beings would only be able to see shapes, lines and points (length and width, second dimension). The part of my belief that frustrates him is that, according to this theory, we are actually four dimensional beings, but can only perceive up to three dimensions, which means that we can only see length, width, and depth, which is why, even though we are from the fourth dimension, we cannot imagine fourth dimensional objects such as tesseracts. His belief is that we are three dimensional beings, and that is why we see in three dimensions. Which theory is more likely? If you have any links to websites or articles that could help my brother and I to better understand this situation, please share! PS: I also believe that the fourth dimension is not time, but another measurement that we are unable to see BECAUSE we are fourth dimensional creatures.