Defending the New Natural Law's Incommensurability Thesis

New Natural Law (NNL) usually gets a bad rap from certain Thomists due to its embracing the "incommensurability thesis." I'll first explain the basic outline of NNL. I'll then explain the incommensurability thesis, and present an argument for it that I find quite convincing. Finally, I'll defend incommensurability from a common objection, and actually show how the objection favors incommensurability. Hopefully my defense will help illustrate the intuitiveness of the thesis.

First, a little explanation of NNL. NNL derives specific moral/practical norms by positing two things:

• (1) A set of basic goods--things that are intrinsically good/valuable/worthwhile for humans to pursue. So, they are always "worthy of pursuit." In other words, they are always "to-be-pursued." Also, the basic goods can make immediately intelligible one's action, and are thus reasons for action. This is very important: The basic goods are the fundamental reasons for action; the fundamental "building blocks" of practical rationality. Examples include knowledge, life, friendship, aesthetic experience, and excellence in play.
  
  Let's consider an example. For instance, suppose you ask me, "Why are you running?" and I say, "To help my heart get stronger," to which you reply, "Why do you want to make your heart stronger?" If my answer is, "For the sake of my health, that I might live and live to the full," then this is a "question-stopper;" you can immediately see why I might want to do this, and thus health is a reason for acting that makes my action immediately intelligible; it immediately "make sense." This is because acting for the sake of someone's health is intrinsically valuable and worth doing.
  
  This is the first part of NNL: There is a set of basic goods, as defined above.
• (2) A set of principles of practical reasonableness--these are principles or rules that tell us how it is reasonable to respond to instances of the basic goods. Examples include the golden rule, the prohibition against directly intending to harm a basic good for the sake of something else, rules against arbitrarily discriminating against the goods of certain people, the rule of being reasonably efficient in how one pursues one's plans, etc.

So, we start out with a list of things that are intrinsically good for us to pursue, and then there are rules that tell us how it is reasonable for us to go about pursuing them. The list of goods, in conjunction with the rules for practical reasonableness, ultimately tell us what actions are permissible as well as what actions are obligatory. They tell us what we may permissibly do, as well as what we ought to do. These rules are taken to be constitutive of practical reasonableness; they are supposed to follow from the very nature of practical rationality.

Much more needs to be said here obviously. Many books have been written. However, I don't need to get too much into the details of this for the sake of my post here. That's just the basic idea.

Now, one of the ideas about the basic goods that motivates some of the principles of practical reasonableness is the incommensurability thesis. Here is the thesis of incommensurability:

• (INC) For each basic good x, it is not the case that x offers all the goodness ("to-be-pursuedness") of some other basic good and more.

See, for instance, Christopher Tollefsen's helpful paper. NNL theorists use the incommensurability thesis to present what I think is one of the strongest arguments against consequentialism of any sort.

Now, the motivation for the incommensurability thesis, as I've stated it, is that it seems that each good is beneficial to humans in a way which none of the other goods is. It has a unique type of goodness. Health is good for us in a way that knowledge is not, which is good for us in a way that friendship is not, and so on. If on the other hand we supposed the contrary of incommensurability, then some basic good x would offer all the goodness and more of some other basic good, say y. But then it's hard to see how y could make one's action immediately intelligible (which is part of the definition of a basic good). After all, if someone says, "I did this action for the sake of y," then in some circumstances you can reasonably say, "Well, you should have acted for the sake of x instead, since it offers all the goodness and more of y. So why didn't you?" In which case y would not be a basic good, since acting for the sake of y should make one's action immediately intelligible, and in this case it doesn't. But that's a contradiction, since we assumed y is a basic good. So the incommensurability thesis is true.

Now, one objection is that it seems we should be able to prioritize the goods. Religion is more important than life, life is more important than knowledge, knowledge is more important than fun, and so on. This seems plausible to some. But, if NNL is right, none of these can be "weighed" against the others, since none of them offers all the goodness of any of the others and more. So, the objection goes, if incommensurability holds, then we can't prioritize the goods.

External Reasons: A Natural Law Response to Williams

In my last post I criticized Bernard Williams' rather Humean argument in "Internal and External Reasons" for arguing that external reasons can't explain action. As a follow up, I wanted to post my paper I wrote for the meta-ethics class I'm taking where I criticize further Williams' argument against externalism, and at the same time build up a natural law account of reasons and practical rationality in opposition to Williams. Here it is!

                      In “Internal and External Reasons,” Bernard Williams presents an argument for thinking that external reasons do not exist, and thus all external reasons statements are false.[1] In this paper I will do three things. First, I will explain what Williams understands internal reasons and external reasons to be. I will then explain Williams’ argument against external reasons. Finally, I will attempt to give some defense of external reasons by critiquing Williams’ argument.

                      The general form of a reasons statement is “A has reason to do F in circumstances C.” Williams aims to show that statements of this form are only ever true on an internal interpretation. While Williams does not seem to give a definition of internal reasons statements, he does lay out what seems to be a necessary condition on internal reasons statements. He says that any internal interpretation of a reasons statement must “display a relativity of the reason statement to the agent’s subjective motivational set,” which we shall call “S.”[2] Roughly then, internal reasons for an agent are dependent on what is in the agent’s subjective motivational set.[3]

                      Williams also lays down as a necessary condition on internal reasons that they can be discovered by deliberative/practical reasoning.[4] While Williams does not explicitly define what deliberative or practical reasoning is, he specifies his conception of deliberative/practical reasoning via example. In particular, he says that practical reasoning includes means/end reasoning about the most preferable way of satisfying a desire, temporal ordering of when to satisfy which desires, determining which desires one is most interested in satisfying, and determining what would constitute satisfaction of one’s desires. So, this condition amounts to saying if A has an internal reason to F, A must be able to motivate herself to F by a process of reasoning of this sort (from S).[5]

                      It is clear then that Williams is working with an idea of internal reasons that ties them closely to an agent’s current subjective motivational set. It is also clear that he is working with a “thin” notion of practical rationality. Since Williams doesn’t explicitly define what he takes rational deliberation to be, it is difficult to precisely state what this “thin-ness” amounts to. However, roughly speaking, Williams’ account of rationality is “thin” insofar as, on his view, a decision will count as rational to the extent that it could be concluded to by a process of deliberation starting from one’s desires and satisfying certain (relatively weak) formal constraints.

Bernard Williams on Internal Reasons (Contra Natural Law)

Here is a short precis I wrote for my meta-ethics class about Bernard Williams' argument for internalism about reasons. Internalism about reasons is, roughly, the Humean-ish idea that an agent has a reason to act a certain way only if it is somehow grounded in the desires of the agent. This is directly contrary to the natural law view, according to which what is reasonable to do or not to do is independent of the desires of the agent, and thus reasons are independent of an agent's desires:

In “Internal and External Reasons,” Bernard Williams presents an argument for thinking there is a problem with external reasons statements.[1]

1.    If something R can be a reason for action, then R can be a reason for someone A’s acting on a particular occasion O. [Premise]

2.    If R can be a reason for A’s acting on a particular occasion O, then R can figure in an explanation of A’s acting in O. [Premise]

3.    So, if R can be a reason for action, then R can figure in an explanation of A’s acting in O. [1,2 HS]

4.    If R can figure in an explanation of A’s acting in O, then R cannot be an external reason. [Premise]

5.    So, if R can be reason for action, then R cannot be an external reason. [3,4 HS]

6.    If R cannot be an external reason, then R is an internal reason. [Premise]

7.    So, if R can be a reason for action, then R is an internal reason. [5,6 HS][2]

Hence, the argument establishes that the only coherent notion of a reason for action is an internal reason for action, i.e., one which is relative to an agent’s subjective motivational set S. For now, let us grant premises 1 and 6. I’d like to think about premises 2 and 4 a bit. My point will be that, depending the sense of ‘explanation’ here, either one or the other premise will be implausible.

                      First, let us consider the interpretation of explanation where an explanation of an action is something that (directly) motivates someone to do that action. In this sense, maybe we should accept 4. For maybe it is only one’s desires, or at least something closely bound up with one’s desires, that could explain an action in the sense of being able to directly motivate it.[3]

                      However, in this case, I think that premise 2 is implausible; for I don’t think that a reason for acting in an occasion has to be able to motivate you. Rather, a reason for performing P in circumstance C is some state of affairs or consideration that could make performing P in C practically intelligible.[4] And something can do this without being able to motivate. Let me explain.

                      If you found me in a chair stabbing myself in the leg you would ask me why I’m doing what I’m doing. If I said to you, “I just desire to,” this wouldn’t really answer your question. There is still a clear sense in which what I’m doing is unintelligible, and wouldn’t make sense even if I obeyed some bizarre psychological laws which led me to “just desire” to stab myself in the leg. If however I said, “I am scared there is a tiny alien in my leg, and I need to get it out so it doesn’t kill me,” I will at least have described some state of affairs where, when my action is seen in light of this, my action does at least become intelligible (even if, in all likelihood, it is still utterly ridiculous and unreasonable). Such a state of affairs is a reason for acting a certain way.

                      But if this is a correct account of what reasons for action are, then 2 seems false. For it might be that a state of affairs S could make doing P intelligible, and thus counts as a reason for doing P, but my subjective motivational set makes me completely unable to even take S into consideration, and thus makes S unable to motivate me. This happens all the time. For instance, suppose I have no desire or motivation to quit smoking. However, the fact that smoking greatly increases my chances of dying certainly could make the action of quitting intelligible (i.e., if someone appealed to this fact when justifying their choosing to quit). So the fact that smoking greatly increases my chances of dying is a reason to quit. Yet, again, it might be that it couldn’t motivate me on any occasion.

                      All of this is to say that, on the interpretation of ‘explain’ where it is roughly equivalent to ‘motivate’, premise 2 seems implausible. On the other hand, if ‘explain’ means ‘make intelligible’, then premise 2 seems true, but premise 4 seems false, at least if reasons for action are, as I’ve explained, states of affairs which make acting certain ways practically intelligible.

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[1] The “problem” is either that they are false, incoherent, or are misleading (and presumably should instead be rephrased as internal reasons statements). See the last paragraph of p. 297.

[2] This is my interpretation of Williams’ argument at the bottom left paragraph of p. 295. I may be misinterpreting Williams, but this seemed to me the best way to make his argument valid.

[3] I am assuming the sense of ‘can’ here means something along the lines of ‘is physically possible’.

[4] This account is largely adapted from G.E.M. Anscombe’s book ‘Intention’, sec. 37.