I am in the middle of Rene Descartes Meditations on First Philosophy and while also reading Martin Luhers On Christian Liberty. Descartes was writing about 100 years after Luther but both men come across to me as revolutionaries in the way they thought of their respective subjects. With Luther we have this disaffected German monk who is trying to peal away centuries of detritis from Christian worship and get back to, as he saw it, a purer form of faith based worship while rejecting worldly works. His point that "a house never built a hammer" is as excellent an example as I can think of to spell out his belief that faith must come before works. Or take his notion that a Christian is totally free and subject to no earthly power. That was radical in an age of emperors, popes and kings. Not that I agree with him in totality on all counts. However in the age of Luther this was radical enough to cause a war that lasted 30 years.
Descartes by contrast was a Catholic scientist who decided to peal away all the philisophical detritis of the passed centuries to attain a purer philosophy regarding how we know what we know. He joined the army and spent time on campaign in centeral Europe. He is the quintessential doubter of everything. "I think therefore I am." seems pretty straightforward until you delve into his meditations. I am comming away with a great respect for Descartes for his ability to mathematically turn aside all presupositions and, trusting only that he thinks, building a philosophy that stands on modern scientific grounds.
Both these guys have had great influance on the course of Western Civilization. I see in both their writings glimpses of the Declaration of Independance and Constitution that would come into existance a century later. Luther would say that a man's faith his between him and God and that no earthly power could either justify him before God nor banish him from God's sight. In other words governments really can't do much regarding religion and it would be better to keep them out of it entirely.
In actuality the Holy Roman Empire did practice a form of religious tolerance for pretty much any sect. And while they did this the religious terrorism that was endemic in many places in Europe was not evident in the Empire. When Maximillian II took the throne, being a staunch supporter of the Catholic cause, the emprie was plunged into religious warfare ending in the empires eventual destruction.
I was amazed and hartened a week ago when I heard Justice Stephan Bryer talk about the Supreme Courts thinking on the seperation of church and state. In that talk he too brought up the sectarian religious wars spawned by the advent of Luther inwhich Rene Descartes marched and thought.
Compared to Descartes and Luther, Karl Marx reads like even more of an idiot.