PAB 154-scale of reality
The Scale of Reality is employed here, and this is why it is done. 
(Scale of Reality: At the bottom there is nothing; above that there is a communication line, the line becomes more solid, then above that terminals begin to materialize lightly and the line becomes less solid, then above that you have the terminals and you don’t have any lines, and above that the terminals are there mostly by agreement; above that there is agreement, and above agreement there is consideration, individual consideration, and above that there is postulate. That is the Scale of Reality.) 

postulate
individual consideration
consideration
agreement
terminals are there mostly by agreement
terminals and no lines
light terminals and light lines 
solid lines 
communication line
nothing