Comprehending the shift requires understanding pagan European philosophies of nature in a bit more detail. As I said earlier, pagans tend to see natural forces and objects as inhabited by consciousness; but apart from such directly experienced aspects of nature, the spirit world was inhabited by what Jung called archetypes. The gods personify certain abstract qualities of human life: love, war, beauty, wisdom, male, female, youth, old age, and so on. Of course, belief in such gods was discouraged once Christianity came along. But among the literate classes at least, a more highbrow philosophical version survived through Christians adopting the classical Greek concept of universals.
Here I admit that my lack of philosophical education will probably make me screw something up, so I cede the floor to David Opderbeck:
Philosophically, the question relates to whether “universal” substances exist apart from their particular instantiations (“universals”), or whether substances are merely names for particular instances of things (“nominalism”).
Consider an apple. What is an apple? Is this particular apple on my kitchen table one instantiation of the substance “apple” – a substance with some sort of universal metaphysical (“beyond-“ or “above-“ physical) properties that are shared by all apples? Or is “apple” simply a name I apply to this object before me as a result of some observable similarities with other objects (other things we also call “apple”) that have no metaphysical connection to the “apple” on my table?
Opderbeck and Taylor both point to 13th-century thinker William of Occam as the prime example of the shift to the modern view, called nominalism, and it was driven by a concern for God's sovereignty. As Taylor says: "The Aristotelian notion of nature seems to define for each thing its natural perfection, its proper good. This would be independent of God's will, except that he it is who created the thing thus. But once created, it would appear that God cannot further redefine what the good is for that thing." Nominalism, on the other hand, sees things as instruments of God's will, as interlocking parts in his ongoing project.
For many who claim a modern scientific worldview, there are only particular objects called “apple,” which are more or less related to other particular objects in morphology and chemical composition, all of which are categorized as “apples” for the sake of convenience. What is “real,” in this view, is merely chemistry and physical laws, not any substance “apple.” In contrast, for those who believe in universal properties, “apple” implies properties that are real and transcendent of any one apple.
That at first might not sound very scientific. This is the God of Intelligent Design, the God of the purpose-driven life, and (much to Opderbeck's annoyance) the God that a great many American conservative Protestants believe in. But nominalism also did something extremely necessary in the move toward modern science, in that it turned the material world into inert "stuff," whose meaning and purpose comes only from the intelligence who created it and uses it. Nature is no longer archetypal, but instrumental.
This discussion was rather difficult for me to follow, but if I understand it right it does help to clarify the difference between "purpose" as understood in, say, Thomas Aquinas and other Natural Law theorists, and "purpose" in modern scientific thinking. I mean, while it's true that some will say that purposelessness is the defining characteristic of scientific materialism, on the other hand the narrative of cause and effect does make it possible for, say, a scientist to agree that sex is "for" reproduction. What's lacking is the inherent connection between the general purpose and every particular instance, and along with it the connection between form and function. So, for instance, conception achieved in a lab instead of in a woman's body equally well achieves the purpose of reproduction; conversely, if you cancel the reproductive purpose of sex through birth control or sodomy, and use it for your own emotional fulfillment, then that becomes the purpose of that particular sex act just as surely as reproduction is in another case. The idea of universals, by contrast, seems to say that only reproductive sex is the universal form, and while you may more or less tolerate deviance in individual instances, those deviations can never really participate in the universal.
This, I think, pretty well explains how the culture war has gone. Because if I have trouble wrapping my head around universals -- and I am both attracted to mythopoetic thinking and kind of a prude -- then it's going to be pretty well impossible for someone with more skin in the game, like a partnered gay person. Because we moderns live in a completely instrumental world. I mean, the archetypes are nice in theory, but I have no idea how to actually live as both a woman and as an instance of Woman. Without a sense of the reality of the universal, this idea simply turns into a pile of pointless restrictions: you can't do this or that because you're a girl.
Even the conservative side of the argument tends to think instrumentally: traditional marriage and family are good for society because statistically children are better off in this way and that. But as Eve pointed out a while ago, statistics can't entirely resolve our moral problems -- in part because we have to decide beforehand just what purpose we're using them for.
But anyway, long before these culture-war arguments broke out, the shift towards nominalism was changing society. The next post will look at how that began to play out.