All other dimensions are bound by the 2nd to be functionally a dimension.
So if it wasn't for the 2nd dimension, all the other dimensions wouldn't be dimensions? What would they be then?
A fourth dimension would be truely another 3rd, an extention of a third in spacial time.
That's true in a sense. Actually all the dimensions are the same. To prove this, turn to face another direction. You'll find that the dimensions have suddenly switched places, and yet you're still in the same universe, with all the physics intact.