Void House Book Club: Groundwork of the Metaphysics of Morals

When we discuss history, we put a pin in the birth of Jesus and describe all events as happening some amount of time before or after it. We could do something similar in philosophy with the publication of Rene Descartes’ Meditations on First Philosophy. Meditations raised a question which philosophers grappled with for centuries: how can we know anything with certainty? If our perceptions are ever mistaken, how do we know that anything we perceive is true and not merely a flawed interpretation? This question had existed in the philosophical world for a long time, but many philosophers ignored it because it didn’t lead to any conclusions. The Roman skeptics introduced the problem of the criterion, which argued that any given statement is knowable only because of some other statement, which is itself only knowable because of some third statement, and onwards into infinity. You can see that it’s impossible to prove or refute this statement, because any proof or refutation would depend on postulates that themselves needed proof and refutation, so why even bother talking about it?

Descartes found a solution. He argued that there is a statement which is not contingent on any criterion, because it is contingent on itself: “I exist.” Obviously, in order to assert existence, something must exist. Further, this criterion can be used to justify other criteria, and thus we can develop from this singular statement an entire system of philosophy that requires no assumptions or guesswork — only pure reason.

Unfortunately, while Descartes proved that the mind is real, he failed to demonstrate that human perceptions reflect reality. His argument was that an all-loving and all-powerful God would not trick humans into misinterpretations, which I hope you can understand is not a very convincing argument. Thus, a new school of philosophy dedicated itself to the construction of philosophy built on pure reason, calling themselves the rationalists. This was a daunting task, especially given opposition from another school, the empiricists. One empiricist, David Hume, even made the remarkable claim that no one event is caused by another — we assume so because, from past experience, we always see one event following another, but that doesn’t actually mean that one caused the other. Thus, the rationalists found themselves in an unenviable position.

From this tradition emerged Immanuel Kant, one of the great epistemological thinkers. He argued that “I exist” is not the only first principle, but that because human experience relies on such concepts as the existence of space and time (and causation!), it follows that these are also true a priori, at least in terms of human experience. The thing-in-itself is unknowable, but that’s okay. We only need to know about real things in terms of how they relate to us. Before Kant, epistemologists argued about how reality really was, with human experience revolving around reality as merely tertiary. When Kant centralized human experience and made reality tertiary, he called it his “Copernican Revolution.”

In my opinion, this solves the problem. I understand that not everyone finds it satisfying, but I maintain Kant was right that certain axioms — such as “my consciousness exists,” “space and time exist,” “events have causal relationships,” etc. — do not require justification, and from there we can construct a rough approximation of reality, at least as it conforms to human experience. We must laud Kant for this achievement. We must also exercise caution when we explore the rest of Kant’s thought.

Kant believed that everything we can know is knowable through the application of reason alone, and not through observation of the material world. One consequence of this idea is that, again through the application of only reason, a person could always choose the “ethical” action, which Kant defines as that motivated by good will. Now, there is a lot of fuzziness here, notably that in order to act on good will, one must know what is and isn’t good, and it’s not clear that’s possible through reason alone. However, if we assume that we know what is and isn’t good — perhaps it’s a synthetic a priori truth — then I’m willing to at least make it this far with Kant. The real leap is the categorical imperative. 

A categorical imperative has two qualities: first, it is a rule that one must always follow in all contexts, and second, it is a rule that one must wish to become a universal law (that is, everyone would always follow it in all contexts). Some examples of categorical imperatives include “don’t lie” and “don’t murder.” Kant believes a person is more ethical the more closely he holds to the categorical imperatives. I think my readers probably already see some problems here. I’ll point out three. First, this doesn’t follow from Kant’s argument that we ought to use pure reason to determine what is ethical. Surely that argument only demonstrates that Kant needs to use logic to reach the categorical imperative in the first place, something he fails to do. In fairness, Groundwork of the Metaphysics of Morals is a famously opaque book, and I am not the strongest reader, so I can concede that I might have simply missed something. My other two arguments are stronger, though. Kant does not prove that, because some behavior would be desirable if it were followed by all people in some theoretical world, it is also desirable in our material reality. In a world with no murderers, it might be hard to justify a murder, but murdering one man to save the lives of many is at least more debatable. This brings us to the third issue, which is that categorical imperatives lack nuance. Kant would likely concede that, yes, there are situations in which murder or lying are ethical, but that we should not ditch the categorical imperative. We should just replace our current, flawed categorical imperative with a new one that accounts for those situations. Of course, trying to account for every potential situation is impossible, and we would need to invent more and more stipulations to each rule until eventually following categorical imperatives is no different from assessing each situation as it occurs, which is what most people do anyway.

I was surprised when I was recommended Groundwork of the Metaphysics of Morals, because it does not accord with my beliefs at all. Ethical behavior grows out of virtues, not rules; how could I synthesize Kantian morality into my worldview? The book was short enough for me to read on a single flight, but it is very challenging, and I fear I did not retain enough from it despite reading slowly and carefully. I was impressed by the flow of Kant’s arguments. They read mathematically, clearly deriving conclusions from postulates and Aristotelian rules of logic, such that their validity is undeniable. Unfortunately, he made a jump when he moved from arguing for pure reason to arguing in favor of the categorical imperative, and it’s a jump that I just can’t forgive. It leads to too many errors. I feel vindicated in both my praise and criticism of Kant now that I’ve read some of his work. Not every book you read will change you; Groundwork of the Metaphysics of Morals did not change me.