So the question is: how did we get here from there? How did we go from a situation in which atheism was unthinkable (1500) to one in which it is the “default” position for many (2000)?
Taylor begins by noting three features of the medieval “world” that significantly contributed to the plausibility in conditions in 1500 and thus “made the presence of God seemingly undeniable” (25). He later describes these as “obstacles to unbelief” (29):
1) The natural world was constituted as a cosmos which functioned semiotically to point to what was more than nature;
2) Society itself was understood as something grounded in a higher reality: earthly kingdoms were grounded in a heavenly kingdom;
3) In sum, people lived in an enchanted world.
It’s not that these features guarantee that all medieval inhabitants “believe in God;” but it does mean that, in a world so constituted, “[a]theism comes close to being inconceivable” (26). So some part of the answer to his overarching question is that “these three features have vanished.”
But while that is clearly a necessary part of the story, it is not a sufficient answer to the question: “the rise of modernity isn’t just a story of loss, of subtraction” (26). It’s not just that God is lost in a disenchanted world; it’s also that God is replaced by “exclusive humanism” (26). And if “Man” comes to replace “God,” then “modern humanism…had to produce some substitute for agape” (27).So the “story” of the shift from medievalism to our “secular age” is not just a story of dis-enchantment but also a story about the emergence of “exclusive humanism” as an alternative option (28).