You will also find two rather small books on the nature of Papacy: And On This Rock and The Keys of the Kingdom.
I have no time nor inclination to summarise them - they are both splendid studies - the first of the geographical character of Caesarea Philippi and the use of the term "sur" and "kepha" (rock) in Hebrew Scripture; the second of the nature of the tool called a "key" and its place in technology and symbol.
It may make some people uncomfortable to speak of the papacy, regardless of their place in or out of the Roman Catholic Church - but I wonder. Do these find the same degree of discomfort from the Olympics? Or from the United Nations? Or from the ISO? Perhaps one of the other large international scientific organizations, such as the IUPAC or IUBMB are a source of worry?
I urge you to find these two books and read them and consider them as the work of a scholar on a difficult topic. And ponder, if you will, what another scholar once wrote about the same topic:
There is a famous saying which to some has seemed lacking in reverence, though in fact it is a support of one important part of religion: "if God had not existed, it would have been necessary to invent Him." It is not at all unlike some of the daring questions with which St. Thomas Aquinas begins his great defence of the faith. Some of the modern critics of his faith, especially the Protestant critics of it, have fallen into an amusing error, chiefly through ignorance of Latin and of the old use of the word divus, and have accused Catholics of describing the Pope as God. Catholics, I need not say, are about as likely to call the Pope God as to call a grasshopper the Pope. But there is a sense in which they do recognize an eternal correspondence between the position of the King of Kings in the universe and of his Viceroy in the world, like the correspondence between a real thing and its shadow; a similarity something like the damaged and defective similarity between God and the image of God. And among the coincidences of this comparison may be classed the case of this epigram. The world will more and more find itself in a position in which even politicians and practical men will find themselves saying, "If the Pope had not existed, it would be necessary to invent him."Frankly, I think the scientific community has already done so, hence I am unable to understand the whine sometimes heard about the topic. Perhaps we scientists ought to try being poetical once a year at the very least, and exercise our intellects on ideas such as Rock and Key-Keeper - perhaps then we shall find ourselves refreshed and ready to return to our day-to-day (and far smaller) topics again. For us in the Duhem Society, I recommend this day, February 22, as the most fitting day for such an excursion.
[G. K. Chesterton, The Thing CW3:325]
Postscript: I am also aware that SLJ wrote his theology doctorate on questions about Ecclesiology, but I cannot read French, so I am unable to comment on it at present.