text: Still not there. 
  
  St Thomas taught that all law has 4 elements, and one of those elements is that it follows reason.
  
  Saint JPII said in marvelous and beautiful treatment on truth said: "God provides for man differently from the way in which he provides for beings which are not persons [e.g., the animals]. He cares for man not 'from without' through the laws of physical nature, but 'from within', through reason, which by its natural knowledge of God's eternal law, is consequently able to show man the right direction to take in his free actions." (The Splendor of Truth, Veritatis Splendor, no. 43). 
  
  Natural law is entirely acquirable by observation and reason.     No faith is required. 
  
  CS Lewis became a Christian beginning with sustained rational inquiry about natural law.
  
  The Pope can only bind and losen within the guardrails of the past "binding and loosening".
  
  Unity and depth, again, isn't it marvelous.