I dont quite get why peaple are having truble thinking in 4d, it takes more power, yes, but not that much more and only because more dimentions always take up more power. It might be hard to render in realtime, yes, but that shouldn't prevent thinking about it.
That...no way I mean, how can you do that? Are you honestly capable of imagining all four dimensions, what does that even looks like?
I'm not quite sure how one can be unable to think in 4 dimensions, 5-7 is were one shuld start to have trouble, but really...
As for *rendering* it, that's a bit harder, because you have to convert an n-dimentional procedural or vector format of some kind into a raster grapic with 2 spatial dimentions and 1 time, as that's what the visual cortex is hardwired for, but it's still not that hard at least up to 5 or so.
One easy method is to use two 2d planes, one one you project a "shadow" of the 4d object as a reference, for each point on that image, you then have the other plane take a slice of the other two dimensions
Then you overlay a space filling curve (or just a semi-space filling zigzag for simplicity), and move a point along that curve, and render the corresponding contend of the second plane. and there you have it, 4 spatial dimensions rendered in 2 spatial and 1 time.
You can also use the perspective rendering from 3d to 2d and a volume filling curve to make this work with up to 6 dimensions, provided you have good enough temporal resolution and/or good enough memory. Note that this include BOTH spatial and temporal dimensions.
Also, you if the geometry is simple enough along some dimensions, (just a thickness, or displacement) you can colour code them, combined with the above methods this should let you render AT LEAST 9d, possibly 12d or so, provided that shapes are suited for it.