Richard Carrier not getting an ought from an is

0. Introduction

In the book The End of Christianity, Richard Carrier has a chapter called Moral Facts Naturally Exist, in which he claims to be able to “dispense” with the is-ought problem. I don’t think he does this. I’m not going to look at the whole piece here, because it is quite long, but I intend to come back to it later. I’m just going to look at a few remarks he makes about the ‘is-ought’ problem.

1. The argument

Characteristically, he is quite ambitious:

It’s often declared a priori that “you can’t get an ‘ought’ from an ‘is’,” and that therefore science can’t possibly discover moral facts. This is sometimes called a “naturalistic fallacy.” But calling this a fallacy is itself a fallacy. Indeed, it’s not merely illogical, it’s demonstrably false. We get an “ought” from an “is” all the time.

Given this primer, I am expecting to see the demonstration of how to get an’ ought’ from an ‘is’. That is, I am expecting to see a valid argument, with true premises that are purely descriptive that has a conclusion which contains the word ‘ought’.

Yet, this is not what we get. Here is what we get:

For example, “If you want your car to run well, then you ought to change its oil with sufficient regularity.” This entails an imperative statement (“you ought to change your car’s oil with sufficient regularity”), which is factually true independent of human opinion or belief. That is, regardless of what I think or feel or believe, if I want my car to run well, I still have to change its oil with sufficient regularity

Now hold on a minute. Let’s break this down into the relevant bits. Firstly we have a conditional statement:

1. If you want your car to run well, then you ought to change its oil with sufficient regularity.

We also have an expression of the consequent of this conditional:

2.  You ought to change your car’s oil with sufficient regularity

Yet, contrary to Carrier’s claim, 1 does not entail 2 (if you disagree, please tell me the inference rule used). To make it entail 2, we would have to add in a premise, 1a, about what you want:

1. If you want your car to run well, then you ought to change its oil with sufficient regularity
1a. You want your car to run well
2. Therefore, you ought to change its oil with sufficient regularity (1, 2, modus ponens)

Together, 1 and 1a jointly entail 2 (via MP), but on its own 1 does not entail 2.

Carrier says that 2 is “factually true independent of human opinion or belief”, but it doesn’t follow from 1 unless we have the premise, 1a, which explicitly references what people want. We can, of course, assert that 2 is true independently of human opinion or belief if we like, but we have not shown that it is derived from 1. Asserting that 2 is true surely cannot be held to be an example of deriving an ‘ought’ from an ‘is’; it would be just an assertion of an ‘ought’.

Indeed, Carrier changes scope in the very next sentence, from 2 being what is independent of human opinion of belief, to 1 being independent of human belief:

“That is, regardless of what I think or feel or believe, if I want my car to run well, I still have to change its oil with sufficient regularity”

Clearly, he is now saying that the conditional statement is what is true independently of what people feel or believe. In the previous sentence, he is making a different claim, namely that the consequent is what is independent of what people feel or believe.

But even if the conditional (i.e. 1) is true independently of what people feel or believe, this does not mean that the consequent of the conditional (i.e. 2) is true independently of what people feel or believe. You can’t derive ‘q’ merely from ‘if p, then q’. And you can’t derive ‘q is independent of what people feel or believe’ from ‘(if p then q) is independent of what people feel or believe’.

But perhaps his claim is just that we can derive 2 from 1 and 1a. If so, he is right. And I also think that 1 and 1a are both true. I’m not disputing the logical form of that argument, or either premise. So that argument is both valid and has true premises. Great!

So, what’s the problem? Well, premise 1 has an ‘ought’ in it. So this is not an example of an argument which has an ‘ought’ in the conclusion, but no ‘ought’ in the premises. We are not getting an ‘ought’ from an ‘is’. We are getting an ‘ought’ from an ‘ought’ and an ‘is’. That is not what was advertised.

2. Diagnosis

What is going on here is that we often express the relationship between A and B, where A is something we want and B is the ‘optimal’ way of getting A, by saying that we ‘ought’ to do B. For example, most will happily nod along to the following:

If you want to go to university, and if studying hard for your exams is the optimal way to ensure going to university, then you ought to study hard for your exams. 

But, if you stop to think about it, the relationship between the antecedent and the consequent is not one of logical entailment. That is, the following is logically invalid:

1. You want to go to university, and studying hard for your exams is the optimal way to ensure going to university
2. Therefore, you ought to study hard for your exams.

I admit that this argument sounds valid. It sounds valid, and it has a descriptive premise with a normative conclusion. Contrary to what I’m claiming, many people will think that this is a way to derive an ‘ought’ from an ‘is’.

Regardless of how it seems, strictly speaking it isn’t valid. In reality it is an enthymeme, or an argument in which one premise is implicit. For example, if I say “x is a horse, therefore x is an animal”, we will hear this as valid, but only because the premise “if x is a horse, then x is an animal” is implicit. In formal logic though, we need to state all our assumptions. In the ‘is/ought’ problem, this is also true.

What is implicit in our case is the following premise:

1a. If you want A, and B is the optimal way of realising A, then you ought to do B.

We might have this in our background knowledge, as an implicit assumption, but if we are talking about logical validity (as indeed we are here), then we need to make these explicit. Once we add this new premise in, we can substitute terms from 1 to 1a to get:

1b. If you want to go to university, and if studying hard for your exams is the optimal way to ensure going to university, then you ought to study hard for your exams.

Now, 2 follows from 1 and 1b via modus ponens. That is, the following is valid:

1. You want to go to university, and studying hard for your exams is the optimal way to ensure going to university
1a. If you want A, and B is the optimal way of realising A, then you ought to do B.
1b. Therefore, if you want to go to university, and if studying hard for your exams is the optimal way to ensure going to university, then you ought to study hard for your exams (1, 1a, substitution)
2. Therefore, you ought to study hard for your exams. (1b, 1, modus ponens)

This argument is now formally valid, and the premises are true. But again, we have needed to insert a premise, 1a, which is not purely descriptive – it contains an ‘ought’ in it. Once again, we are not deriving an ‘ought’ from an ‘is’, but are deriving an ‘ought’ from an ‘ought’ and an ‘is’. In addition, 1a does not seem to be something that is empirically discoverable. It looks like a kind of conceptual truth. It doesn’t look like something that science discovered though. Yet it is needed to get to the conclusion.

Carrier says that:

There are countless true imperative facts like this that science can discover and verify, and that science often has discovered and verified, from “If you want to save the life of a patient on whom you are performing surgery, you ought to sterilize your instruments” to “If you want to build an enduring bridge, you ought not to employ brittle concrete.”

I think that what science discovers is something purely descriptive, such as that sterilising your instruments is (part of) the optimal way of performing surgery on patients without them dying. What we discovered is that people much more frequently die if we perform surgery on them with unsterilised instruments. Presumably, we want to ensure that people don’t die when we perform surgery on them. That means we have the thing desired, and (let’s say) an empirically discovered fact about the optimal way to realise that desire. But as we saw above, unless we insert a premise which links what we desire, the optimal way of realising it, and what we ‘ought’ to do, we cannot derive anything about what we ought to do. And that generalised principle, even if it is true, isn’t something science discovered.

His examples only get the varnish of looking valid by smuggling in the premise which mentions ‘ought’. Thus, all of his examples seem to fall foul of the same problem, and none of them are examples of getting an ‘ought’ from an ‘is’.

3. A deeper problem

But, let’s say that we agree that there are basic hypothetical normative facts about the world of the form “if you want to do x, then you ought to do y”. As I mentioned in a previous post, some of these are clearly not moral. Perhaps it is true that if you want to torture someone, you ‘ought’ to kidnap them and tie them up in your basement. Perhaps that is the optimal way of realising your desire to torture someone. A central moral intuition is that, regardless of this empirically discoverable fact about how best to realise your desire, you ought not do that. Some things are wrong, and some things are good, regardless of what we desire. Some things, like torturing innocent people, are wrong even if you are a sadist with a desire to do it; and some things, like helping old ladies across the road (or whatever) are good even if you are selfish and don’t want to do it. Someone who believes that all morality is reducible to hypothetical norms has a very hard time explaining these sorts of situations, where bad things are in line with our desires and good things in conflict with our desires.

I suspect that Carrier wants to say that people with such sadistic (etc) views are irrational somehow, but this seems like an article of faith. Why can’t there be an internally coherent belief set in which someone desires to torture innocent people? Maybe he has a response to this, but I haven’t read enough of his work to know.

Even if there are true hypothetical norms, I think these cannot be the whole story about morality. What we need in addition to these are categorical norms. Carrier’s attempt to say everything we need to about morality purely in terms of hypothetical norms seems to me to be wide of the mark, because it cannot make room in principle for immoral desires, or for moral things that go against our desires.

4. Conclusion

I intend to come back to this essay of Carrier’s, because it has many other seemingly interesting things going on in it. To sum this up, I think he fails to show how to derive an ‘ought’ from an ‘is’, and even if we give him the hypothetical norms he wants, these can never be enough to capture all moral truths.