First off, the Pope is a human being, I doubt there are many Catholic who hold illusions about that. Some popes have gone out of their way, it would seem, to remind us of just how spectacularly weak our mortal flesh can be. We can talk about those guys later. For now, let’s just move away from Renaissance city states and the power politics of that time. Yes, it is fascinating and I’m as intrigued by it as much you are, seriously. Maybe even more.
I could go into the doctrine of the unbroken lineage from St. Peter and the inspiration of the Holy Spirit. If you are struggling with some concepts right now, however, that will only give more side streets to wander down furthering your sense of being lost.
Simply put, the Pope is the Bishop of Rome. He has been elected by the other Bishops who have been appointed Cardinals to unite the church and give guidance as the first among equals.
All Bishops have acquired a fair amount of knowledge about the Church and Canon Law and theology which gives them authority when they speak on these matters. That’s how they got to be Bishops in the first place. It’s more than just getting a new wardrobe including probably the most iconic hat in the church, the pointed duck’s bill, aka the ‘Mitre’ and the additional fashion accessory, the curly topped way tall cane, the crosier.
So, when an issue of doctrine comes up and needs to be dealt with, there is a lot of discussion amongst the bishops, under the direction of the Papo de Papo. His Holiness will listen to their advice, seek consensus and also use discernment based on his own knowledge in contemplating the subject. The conclusion he reaches on the issue is made public as “Ex Cathedra”, (‘from the chair of the church), that is the infallible part.