The Unforgivable Sin of Philosophy?

A standard, albeit potted, way of characterizing the dominant modes of thought for ancient, modern, and postmodern intellectuals is in terms of the relationship between being and knowing. The concept of “being” has to do with metaphysics: what kinds of things exist and how do they relate? The concept of “knowing” has to do with epistemology: what can we know and how can we know it? For the ancient thinker, as the story goes, issues of being were primary and knowing secondary. In the modern era, this relationship was reversed: knowing determines being and not vice-versa. With the so-called postmodern era—an era I think has largely passed—neither being nor knowing are primary: rather our shared use of language determines what we can know, which in turn determines what there is.

I was struck by a comment the philosopher Peter Kreeft made, with respect to the modern thinker Immanuel Kant (1724-1804). Here is the passage, in Kreeft’s book on Heaven:

For Pre-modern philosophy, epistemology, the science of knowledge, must follow metaphysics, the science of being. But for modern philosophy, it is usually the other way round, for the typically modern mind agrees with Kant that knowing determines being, and we cannot know things as they really are in themselves.[1]

So far so good. Kreeft is essentially unpacking what I have noted in my introductory paragraph. But then this:

I have never ceased to be utterly appalled at this idea and to consider it the Unforgivable Sin of philosophy.[2]

The unforgivable sin of philosophy? That is a big claim and I was immediately struck in reading it. After all, rarely in philosophy is there a knock-down argument in favor of one view or another. Almost always, our conclusions are couched in conditionals, qualifications, and codas. But here is a philosopher who says in effect: “Here is a place where philosophy got it wrong. Period. Worse, this wrong has sent much of philosophy on a wild-goose chase, a dead-end path of intellectual pursuit that ends in skepticism and despair.”

I wonder, is there such a thing as an unforgivable sin in philosophy? In other words, is there some idea or set of ideas that are not just false, but responsible for setting philosophy on a trajectory that ends in despair? Let’s assume with Kreeft that there are such ideas. If so, what might they be? (Do you see how I’ve already couched this in a conditional? It is second nature I suppose). Here are some philosophical ideas that I think are not only false, but lead, if followed and applied, to despair and darkness:

In Metaphysics:

“Only physical things exist.” (This is called Global Physicalism). If true, then there is no God, no spirit, (and arguably) no objective moral values.

In Epistemology:

“Knowledge only comes from science.” (This is called Scientism). If true, then there are no non-empirical truths to be known. (Exercise: Scientism is self-refuting. Can you see how?)

In Ethics:

“Anything goes.” (This is called Moral Relativism). If true, there are no objective moral values and either tyranny or anarchy results.

Perhaps my list of unforgivable sins is simply the fruit of the one Kantian sin. Perhaps Kreeft is right that the one unforgivable sin that breads all “lesser” sins is the one he notes. What is clear to me, and hopefully to you, is that there are ideas that are not merely false, but abhorrent because they lead, in the end, to misery and disintegration. The three I list here are a good start. I’m curious to know what other ideas you think stoop to the same level.

[1] Peter Kreeft, Heaven: The Hearts Deepest Longing (San Francisco, CA: Ignatius Press, 1989), 244.

[2] Ibid.