I was watching a documentary entitled, “Quaternity”, by Thomas Joseph Brown, where at 6:30 he was saying that three dimensions are merely “internal” to us (as defined by “Up/Down” (Height), “Left/Right” (Width), and “North/South” (Length)), and that the real dimensions are actually Space and Time. I actually do agree with this idea; the reason being that there are things in this Universe, which are not empirically tangible (such as Ideas, Spirits, Fields, etc.), that cannot be measured by using the three-dimensional coordinate system as tangible objects can. By getting rid of the three-dimensional system as being universal for the two-dimensional system (Space & Time), we can actually include those things that are not tangible as actually being real. Plus, Space and Time are actually universal compared to Length, Width, and Height. For example, Space is a body in which all possible things could happen (not to be too overly idealistic, though), and Time is a body which all manifestations (as causation is) occur in order and simultaneously.
Another possibility that could be on par with this above idea, is the Reciprocal System as propounded by scientist Dewey B. Larson. In this theory, everything is comprised of Motion, in which Space and Time are reciprocals to each other (Three-Dimensional Space and Clock Time, with the extension of Three-Dimensional Time and Clock Space added). Perhaps, both of these theories may be true or synthesized by the common theme that Space & Time are more dominant than the materialist conception of science, being that all things are just three-dimensions with space & time being the setting (or part of some warped continuum as propounded by General Relativity).
Here’s some info on the Reciprocal System.