At heart, what was the Renaissance? How did it contribute to the Reformation?
The Renaissance was fundamentally a rebirth of classical Latin – or rather, the Latin of the first century BC, particularly as it was composed by Cicero (and perhaps Virgil, Livy, Ovid, and other Augustan writers). To Francesco Petrarca, who lived in the fourteenth century AD, this was the pinnacle of its development and worth returning to. Language changes over time, of course – on the ground, Latin morphed into French, Spanish, and Italian – but even as a formal, learned language it changed, such that the Latin in daily use by the medieval Church was not quite the same as the one employed in the Senate House to expose the conspiracy of Cataline. I’m sure that any fourteenth-century reader would have noticed this difference, and not very cared much, but Petrarch cared a great deal. To him, every linguistic change since Cicero was necessarily a debasement, a corruption. (Cicero did employ certain rhetorical effects that later fell out of use.) The venality of the Church, and its stultifying bureaucracy in which Petrarch worked, seemed to be reflected in the prosaic Latin it used.
Thus, to Petrarch, it was a cultural imperative to revive Ciceronian Latin. This project was slightly risqué – Cicero was a pagan, and the Church did not recommend that Christians read too much pagan writing. As it happens, the Church was right – Petrarch almost single-handedly started a vogue for the revival of Ciceronian Latin – and of necessity a revival of the pagan idea of making something of yourself. No longer did life need to be a vale of tears so that one’s heavenly reward could be all the sweeter; now, people started to claim that God had given them talents, and they glorified God when they developed those talents. This is not necessarily anti-Christian, and indeed the Pope later became one of the greatest Renaissance patrons of all, but it did entail a certain skepticism towards traditional Christianity, and the Church that sponsored it. That Lorenzo Valla, using humanist philology, proved conclusively that the Donation of Constantine was a fabrication, is emblematic of this. Emperor Constantine (d. AD 337) did not actually grant to the pope the rights to the papal states, nor the right to name the western emperor. The pope himself invented the notion in the eighth century.
A similar philological critique was launched by Desiderius Erasmus of Rotterdam, who set himself the task of publishing an authoritative edition of the New Testament in Greek. To this end he collected as many manuscripts as possible which, he discovered, did not necessarily agree with each other. To help determine which was the original reading, he adopted the “principle of maximum embarrassment” – that is, the reading that was most likely to be true was the reading that the Church liked the least. In other words, Erasmus implicitly accused the Church of being a bad steward of the Bible. And just as Italian humanists returned to Cicero for his Latin, and for his ideas about human nature, so also did Erasmus believe that this original text ought to be the main arbiter of Christian practice. Thus did Erasmus write Praise of Folly, a scathing attack on the mechanistic, superstitious, non-Biblical Christianity he saw around him. Instead, he believed that everyone should have access to the Bible, so that they could consume the word of God directly.
These two strands, skepticism towards the claims of the Roman Catholic Church, and the idea that we should go back to the Bible to determine our own Christian practice, came together in the program of Protestant Reformer Martin Luther. Everyone knew that the Church was corrupt, in that it often did not live up to its own ideals, but Luther went further than that, and identified non-Biblical Christian practice (starting with purgatory and indulgences) as part of that corruption. If he wasn’t going to be elected Pope, the next best thing would be to get certain German princes to declare their territories free from the Pope’s writ, and reorganize the church there according to his own understanding of Christian practice. And if Luther could do this, then so could others – with or without the support of the local government authorities.
In this way did the Reformation grow out of the Renaissance.