For Kant, and the moderns in general, the notion that the unifying center of a thing really does appear in the individual thing was denied. When I see this particular tree, therefore, all I see is the appearance of this particular tree. If any generalizations are to be made about it, they will have to come from the side of the subject. This means that the classical transcendental properties of Being—unity, truth, goodness, and beauty—must no longer be conceived as properties of Being, but as characteristics attributed to Being from the side of universal subjectivity. All postmodernity has to do to achieve nihilism, it would seem, is to deny any universal subjectivity. Postmodernism is not so much an alternative to modernism as its reductio.
So what does this all mean? Modernity is the attempt to find catholicity apart from particularity. Simply put, modernity wanted Christian “values” without having to put up with the scandalous assertions that (1) one man, a Jew no less, at one particular time and from one particular place, held the key to the meaning of existence; and (2) this man safeguarded this teaching to a particular group of (sinful) men. The Enlightenment could have none of this, and so tried to understand this admittedly important “religion” “within the bounds of reason alone.”
Postmodernity, in its turn, came to regard this enterprise with incredulity. Reason, we are told, cannot and ought not aspire to universality, even if it is an abstracted one. All we have are the competing truth claims of differing cultural-linguistic groups, and the most we can ask for is tolerance of diversity.
Rodney Howsare, ‘What You Need to Know About Hans Urs von Balthasar’