The 4th dimension with Carl Sagan

Prior to watching this video, my thoughts on 2D and 3D were pretty much in line with what was discussed. I had forgotten that a 3D projection in 2D would be distorted so that was definitely an "ah-ha" moment while watching. It was interesting to try to contemplate the existence of a 4th dimension even though there is no real way that we can perceive it. If it is possible that a 4th dimension exists, then why stop there? There may be a 5th, 6th, and 7th dimension that we can't perceive in our 3D level of understanding.  Thinking back about the apple analogy in the video, who knows if there is some other being at work making the Earth move and function in a different way in a higher dimension that we can't perceive?  In my philosophy studies, I'm sure Rene Descartes would have much to say about this notion if it existed during his time. ^_^