This post is going to go down as the dumbest one all week.
You cannot openly be a Catholic and a Mason. Church prohibition.
You can be a Mason and a Catholic and a member of any other religion, so long as you believe in a supreme being. Masonic Code.
If you are an atheist there is nothing for you in Masonry.
Given the current stance of the church it would be impossible to believe that Masonry seeks to install some usurper of the Church.
ecclesiastical masonry
even the freepers chuckle that it cannot exist ... yet some of us smell it every day.