tarotbear
It seems more natural and easier to understand if you intercept the two pillars as Severity and Mercy rather than Law and Liberty. A good reason for that, in my opinion, is that Law and Liberty aren't opposites necessarily. They can be, but not usually.
O.K. - Kabbala takes me out of my comfort zone, but - if you accept the Hierophant (or the HP, Justice, or the Moon cards) as between the Pillars of Severity and Mercy - does that make the Hierophant represent equilibrium & balance - The Middle Pillar?